1. What is authentication bypass?
A) A technique to reset passwords without permission
B) A method to gain unauthorized access by circumventing authentication mechanisms
C) A way to enhance security by using multi-factor authentication
D) A security policy that allows guest users to access an application
Answer: B
Explanation: Authentication bypass occurs when an attacker is able to gain unauthorized access to a system by circumventing its authentication mechanism, exploiting misconfigurations, vulnerabilities, or weak implementations.
2. Which of the following is a common technique for bypassing authentication?
A) SQL Injection
B) Firewall Filtering
C) Network Segmentation
D) Strong Password Policies
Answer: A
Explanation: SQL Injection can be used to manipulate database queries and bypass authentication by altering login validation queries.
3. What payload can be used in SQL Injection to bypass login authentication?
A) ' OR '1'='1' --
B) DROP TABLE users;
C) <script>alert('XSS')</script>
D) SELECT * FROM users;
Answer: A
Explanation: The payload ' OR '1'='1' -- modifies the SQL query to always return true, allowing attackers to log in without valid credentials.
4. Which authentication mechanism is most vulnerable to brute-force attacks?
A) CAPTCHA-based Authentication
B) Password-based Authentication without Account Lockout
C) Multi-Factor Authentication
D) Biometric Authentication
Answer: B
Explanation: If a system does not implement account lockout mechanisms, attackers can use brute-force techniques to guess passwords.
5. What is credential stuffing?
A) Using randomly generated passwords to access accounts
B) A phishing technique to steal credentials
C) Automating login attempts with previously leaked username-password pairs
D) Injecting malicious JavaScript into login pages
Answer: C
Explanation: Credential stuffing attacks use leaked username-password combinations from data breaches to access other accounts where users have reused the same credentials.
6. How does an attacker exploit insecure direct object references (IDOR) for authentication bypass?
A) By altering session tokens in cookies
B) By modifying API parameters to access unauthorized user accounts
C) By injecting malicious JavaScript into forms
D) By performing DNS cache poisoning
Answer: B
Explanation: IDOR vulnerabilities allow attackers to manipulate API requests by changing user IDs or parameters to gain unauthorized access to accounts.
7. What is the purpose of a session fixation attack?
A) To steal session cookies before login
B) To force a user to use a known session ID
C) To exploit SQL Injection vulnerabilities
D) To bypass firewalls using DNS tunneling
Answer: B
Explanation: In a session fixation attack, the attacker sets a predefined session ID for the victim, allowing them to hijack the session once authentication is complete.
8. What type of authentication bypass occurs when an application allows weak default credentials?
A) IDOR
B) SQL Injection
C) Default Credentials Exploit
D) CAPTCHA Bypass
Answer: C
Explanation: Many applications ship with default admin credentials (e.g., admin/admin), which attackers exploit to gain access.
9. Which tool is commonly used for brute-force attacks against login pages?
A) Wireshark
B) Burp Suite
C) Hydra
D) Metasploit
Answer: C
Explanation: Hydra is a powerful tool used for brute-forcing login credentials on web applications, SSH, RDP, and more.
10. How does OAuth misconfiguration lead to authentication bypass?
A) By allowing users to register with fake email addresses
B) By enabling open redirection vulnerabilities
C) By not validating state parameters in authentication flows
D) By using weak hashing algorithms
Answer: C
Explanation: If OAuth implementations do not validate the state parameter properly, attackers can perform CSRF attacks and gain unauthorized access.
11. What is a common method attackers use to bypass CAPTCHA on login pages?
A) Using headless browsers and automated scripts
B) Performing SQL Injection
C) Exploiting buffer overflow vulnerabilities
D) Running a DoS attack
Answer: A
Explanation: Attackers use automated scripts and AI-based CAPTCHA solvers to bypass CAPTCHA protections.
12. How does Cross-Site Request Forgery (CSRF) help in authentication bypass?
A) By injecting malicious JavaScript into the login form
B) By forcing a logged-in user to perform actions without their consent
C) By brute-forcing weak passwords
D) By modifying firewall rules
Answer: B
Explanation: CSRF tricks an authenticated user into executing unwanted actions, which can be exploited to change passwords or escalate privileges.
13. What is JWT cracking?
A) Exploiting weak JSON Web Tokens to bypass authentication
B) Injecting SQL payloads into JWT headers
C) Using CAPTCHA solvers to bypass authentication
D) Modifying DNS records for authentication bypass
Answer: A
Explanation: Weakly signed JWTs can be cracked by altering the signature algorithm or using brute-force attacks.
14. What vulnerability allows attackers to impersonate users by modifying session cookies?
A) SQL Injection
B) Session Hijacking
C) Buffer Overflow
D) DNS Spoofing
Answer: B
Explanation: Session hijacking involves stealing or modifying session cookies to take over user accounts.
15. What is the primary reason why weak password reset mechanisms can lead to authentication bypass?
A) They store passwords in plaintext
B) They allow attackers to modify request parameters to reset any account’s password
C) They use biometric authentication
D) They require two-step verification
Answer: B
Explanation: Insecure password reset flows may allow attackers to change another user’s password by modifying email or token parameters.
16. What is a Null Byte Injection attack in authentication bypass?
A) A method to inject malicious SQL commands
B) A technique to bypass authentication by appending a null character %00 to input fields
C) A phishing attack targeting login pages
D) A way to exploit weak encryption algorithms
Answer: B
Explanation: Null Byte Injection exploits improper input handling by adding %00, which can terminate authentication validation logic.
17. Why is two-factor authentication (2FA) effective against authentication bypass attacks?
A) It prevents credential stuffing
B) It blocks SQL Injection
C) It encrypts session tokens
D) It allows password reuse
Answer: A
Explanation: 2FA adds an extra layer of security, preventing attackers from accessing accounts even if they have stolen credentials.
18. How does social engineering contribute to authentication bypass?
A) By manipulating users into revealing their credentials
B) By injecting malicious JavaScript
C) By exploiting API vulnerabilities
D) By modifying TCP/IP headers
Answer: A
Explanation: Social engineering techniques like phishing and impersonation trick users into providing login credentials.
19. What is the impact of using weak hashing algorithms for password storage?
A) Attackers can brute-force passwords faster
B) It improves authentication speed
C) It makes password recovery easier
D) It prevents authentication bypass
Answer: A
Explanation: Weak hashing algorithms like MD5 and SHA-1 allow attackers to crack stored passwords quickly using precomputed hash tables.
20. What security measure helps prevent session fixation attacks?
A) Regenerating session IDs after authentication
B) Allowing multiple active sessions
C) Storing passwords in cookies
D) Using CAPTCHA on login pages
Answer: A
Explanation: Regenerating session IDs upon login prevents attackers from forcing a victim to use a predefined session ID.
21. What is an OAuth token leakage attack?
A) When an attacker gains access to OAuth tokens via insecure storage or URL exposure
B) When users lose their authentication tokens after logging out
C) When OAuth tokens expire before their intended lifespan
D) When an attacker uses brute force to guess an OAuth token
Answer: A
Explanation: OAuth token leakage occurs when access tokens are exposed in URLs, logs, or client-side storage, allowing attackers to hijack user sessions.
22. Which HTTP header helps prevent authentication bypass attacks by enforcing security policies?
A) X-Frame-Options
B) Strict-Transport-Security
C) Content-Security-Policy
D) Authorization
Answer: D
Explanation: The Authorization header is used to enforce authentication mechanisms, ensuring secure access to protected resources.
23. What is a common method for bypassing CAPTCHA challenges?
A) Exploiting CSRF vulnerabilities
B) Using Optical Character Recognition (OCR) and AI models
C) Injecting SQL commands into the login form
D) Modifying TCP packets
Answer: B
Explanation: Attackers use OCR and AI-driven bots to bypass CAPTCHA challenges by recognizing and decoding the CAPTCHA images.
24. What vulnerability allows attackers to bypass authentication by exploiting a weak password reset mechanism?
A) Insecure Direct Object Reference (IDOR)
B) Weak JWT Signing
C) Password Reset Token Hijacking
D) Clickjacking
Answer: C
Explanation: Weak password reset mechanisms may allow attackers to intercept or predict password reset tokens, gaining unauthorized access to accounts.
25. How can attackers exploit open redirects to bypass authentication?
A) By injecting JavaScript into a login page
B) By redirecting users to a phishing site to steal credentials
C) By modifying the .htaccess file
D) By using DNS poisoning
Answer: B
Explanation: Open redirect vulnerabilities allow attackers to redirect users to fake login pages where they enter their credentials, which are then stolen.
26. What is a session prediction attack?
A) A method to guess a user’s session ID and hijack the session
B) A way to reset passwords using social engineering
C) An attack that involves brute-forcing authentication forms
D) A technique used to predict CAPTCHA challenges
Answer: A
Explanation: If a web application generates weak or predictable session IDs, attackers can guess them and hijack user sessions.
27. How does HTTP downgrade (SSL Stripping) affect authentication security?
A) It forces connections from HTTPS to HTTP, exposing login credentials
B) It encrypts authentication cookies for better security
C) It makes passwords stronger by hashing them twice
D) It prevents brute-force attacks
Answer: A
Explanation: SSL stripping forces users onto an insecure HTTP connection, allowing attackers to intercept login credentials in plaintext.
28. What is a race condition attack in authentication?
A) Exploiting simultaneous login requests to bypass authentication
B) Using a botnet to perform DDoS attacks on a login page
C) Modifying URL parameters to gain unauthorized access
D) Injecting malicious cookies to hijack sessions
Answer: A
Explanation: Race conditions occur when multiple login requests are processed simultaneously, potentially leading to authentication bypass or privilege escalation.
29. What is a token re-use attack in authentication?
A) Reusing an expired session token to gain unauthorized access
B) Resetting a user’s password via brute force
C) Using phishing attacks to steal authentication tokens
D) Exploiting API rate limits to send multiple authentication requests
Answer: A
Explanation: If authentication tokens are not properly invalidated upon logout, attackers can reuse them to access accounts.
30. What vulnerability occurs when authentication logic relies only on client-side validation?
A) Time-of-Check to Time-of-Use (TOCTOU)
B) Insecure Direct Object Reference (IDOR)
C) Client-Side Authentication Bypass
D) Buffer Overflow
Answer: C
Explanation: If authentication is enforced on the client side (e.g., JavaScript validation), attackers can modify client-side code to bypass security checks.
31. Which attack involves replaying intercepted authentication requests to gain access?
A) Brute-force attack
B) Replay attack
C) XSS attack
D) CSRF attack
Answer: B
Explanation: Replay attacks involve intercepting and resending authentication requests to bypass login mechanisms.
32. How do attackers exploit biometric authentication bypass techniques?
A) By injecting SQL payloads
B) By using AI-generated deepfake fingerprints or facial images
C) By modifying firewall rules
D) By altering the DNS cache
Answer: B
Explanation: Advanced attackers use deepfake AI models to generate synthetic fingerprints or facial data to bypass biometric authentication.
33. What security feature helps prevent replay attacks?
A) Rate limiting
B) Nonces and timestamps
C) CAPTCHA
D) HTTP Cookies
Answer: B
Explanation: Nonces (random one-time values) and timestamps ensure that authentication requests cannot be reused in replay attacks.
34. What is HTTP parameter pollution (HPP) in authentication bypass?
A) Injecting multiple authentication parameters to manipulate login logic
B) Using large HTTP requests to crash a server
C) Bypassing authentication using weak encryption
D) Exploiting an insecure API token
Answer: A
Explanation: HPP occurs when attackers send multiple HTTP parameters in a request to override authentication mechanisms.
35. Why is an account enumeration vulnerability dangerous in authentication?
A) It allows attackers to determine valid usernames or emails
B) It enables attackers to inject JavaScript into login forms
C) It crashes the login system via buffer overflow
D) It forces the use of weak passwords
Answer: A
Explanation: If a system provides different error messages for valid and invalid usernames, attackers can identify registered accounts and target them.
36. How do attackers use JSON Web Token (JWT) none algorithm attacks?
A) By modifying JWT headers to disable signature verification
B) By brute-forcing the JWT secret key
C) By injecting SQL commands into a JWT
D) By modifying CAPTCHA responses
Answer: A
Explanation: If an application allows the none algorithm in JWTs, attackers can modify the payload without validation, leading to authentication bypass.
37. What security feature helps protect authentication tokens from theft via JavaScript attacks?
A) HTTP-Only Cookies
B) Plaintext Storage
C) Open Redirects
D) Default Credentials
Answer: A
Explanation: HTTP-Only cookies prevent JavaScript from accessing authentication tokens, protecting against XSS attacks.
38. What is an authentication race condition?
A) Exploiting simultaneous login requests to bypass authentication
B) Brute-forcing credentials using a botnet
C) Performing CSRF attacks against authentication endpoints
D) Injecting session hijacking scripts
Answer: A
Explanation: Race conditions occur when two or more authentication requests are processed simultaneously, leading to unintended privilege escalation.
39. What attack involves changing HTTP request methods (e.g., from GET to POST) to bypass authentication?
A) HTTP Verb Tampering
B) Brute Force Attack
C) SQL Injection
D) Session Fixation
Answer: A
Explanation: Some poorly designed authentication systems process authentication differently based on HTTP methods, allowing bypass via verb tampering.
40. What is the best mitigation against password spraying attacks?
A) Enforcing account lockout after failed attempts
B) Disabling CAPTCHA
C) Using plaintext password storage
D) Allowing default passwords
Answer: A
Explanation: Account lockout mechanisms prevent attackers from attempting multiple common passwords across multiple accounts.
41. How does a padding oracle attack help bypass authentication?
A) By guessing a user’s password through brute force
B) By exploiting cryptographic padding errors to decrypt authentication tokens
C) By injecting SQL commands into the login form
D) By modifying API request parameters
Answer: B
Explanation: A padding oracle attack exploits vulnerabilities in encryption padding mechanisms, allowing attackers to decrypt authentication tokens and bypass authentication.
42. What is the main weakness of using security questions for authentication?
A) They are difficult to remember
B) They can be guessed or obtained via social engineering
C) They use encrypted storage
D) They require two-factor authentication
Answer: B
Explanation: Security questions often use personal information that can be guessed, found online, or obtained through social engineering.
43. What is a bearer token in authentication?
A) A token that represents an identity without requiring reauthentication
B) A hash value generated for password storage
C) A security challenge requiring CAPTCHA verification
D) A method of preventing SQL injection attacks
Answer: A
Explanation: A bearer token allows access to resources without reauthentication, meaning attackers who steal the token can use it to bypass authentication.
44. How can attackers use a Cross-Origin Resource Sharing (CORS) misconfiguration to bypass authentication?
A) By sending authentication requests from an attacker-controlled website
B) By injecting malicious JavaScript into a login form
C) By performing brute force attacks against login credentials
D) By modifying TLS certificates
Answer: A
Explanation: A CORS misconfiguration can allow malicious websites to make unauthorized authentication requests on behalf of victims.
45. Which HTTP header can help prevent authentication bypass through clickjacking?
A) X-Frame-Options
B) Content-Length
C) Access-Control-Allow-Origin
D) ETag
Answer: A
Explanation: The X-Frame-Options header prevents web pages from being embedded in iframes, which mitigates clickjacking attacks.
46. How does a response manipulation attack bypass authentication?
A) By modifying HTTP response headers to indicate successful authentication
B) By using brute force to crack passwords
C) By injecting JavaScript into the login page
D) By performing a man-in-the-middle attack
Answer: A
Explanation: Attackers can intercept and modify HTTP responses to falsely indicate authentication success, tricking users into thinking they are logged in.
47. Why are weak session expiration policies a security risk?
A) They allow brute force attacks
B) They allow attackers to reuse old session tokens
C) They make passwords easier to guess
D) They slow down authentication requests
Answer: B
Explanation: If session tokens are not expired after logout or inactivity, attackers can reuse them to bypass authentication.
48. What is a CAPTCHA relay attack?
A) Using automated bots to crack CAPTCHAs
B) Sending CAPTCHAs to real users to solve on another platform
C) Encrypting authentication tokens using CAPTCHA-based encryption
D) Injecting CAPTCHAs into SQL queries
Answer: B
Explanation: In CAPTCHA relay attacks, attackers trick real users (e.g., through fake tasks or captchas-for-hire services) into solving CAPTCHAs for them.
49. Which attack exploits the use of predictable authentication tokens?
A) Brute force attack
B) Token Prediction Attack
C) SQL Injection
D) Phishing
Answer: B
Explanation: If authentication tokens are generated using predictable patterns, attackers can guess them and bypass authentication.
50. What is OAuth token impersonation?
A) Using stolen OAuth tokens to gain access to a user’s account
B) Bypassing authentication by brute-forcing passwords
C) Injecting SQL queries into OAuth authentication
D) Modifying TLS encryption settings
Answer: A
Explanation: OAuth token impersonation occurs when an attacker steals and reuses OAuth access tokens to authenticate as another user.
51. What is an “unvalidated redirect” vulnerability?
A) A vulnerability that allows attackers to redirect users to malicious sites
B) A method of brute-forcing authentication
C) A flaw that allows bypassing CAPTCHA challenges
D) A type of API misconfiguration
Answer: A
Explanation: Unvalidated redirects allow attackers to send victims to malicious sites, often used for phishing and stealing authentication credentials.
52. What is an API key leak?
A) A scenario where API keys are exposed publicly, allowing unauthorized access
B) A way to bypass authentication using brute force
C) A method of encrypting authentication tokens
D) A vulnerability in CAPTCHA systems
Answer: A
Explanation: If API keys are hardcoded in applications or exposed in public repositories, attackers can use them to bypass authentication and gain unauthorized access.
53. Which of the following is an effective defense against brute-force login attempts?
A) Rate limiting and account lockout mechanisms
B) Allowing unlimited login attempts
C) Encrypting passwords using SHA-1
D) Disabling TLS encryption
Answer: A
Explanation: Rate limiting and account lockout prevent repeated login attempts, mitigating brute-force attacks.
54. Why is multi-step authentication better than single-step authentication?
A) It reduces the chances of authentication bypass by requiring additional verification
B) It slows down the authentication process
C) It increases server load
D) It allows users to reuse weak passwords
Answer: A
Explanation: Multi-step authentication (e.g., 2FA) adds additional security layers, making it harder for attackers to bypass authentication.
55. How does an attacker perform a “cookie tossing” attack?
A) By injecting forged cookies into a user’s browser
B) By brute-forcing authentication tokens
C) By modifying server-side authentication logic
D) By injecting SQL queries into login forms
Answer: A
Explanation: Cookie tossing involves injecting unauthorized cookies into a user’s browser, potentially leading to session hijacking.
56. Why is it dangerous to use HTTP for transmitting authentication credentials?
A) Credentials are sent in plaintext and can be intercepted
B) It prevents phishing attacks
C) It makes session hijacking harder
D) It forces users to use strong passwords
Answer: A
Explanation: HTTP transmits authentication credentials in plaintext, allowing attackers to intercept them using man-in-the-middle attacks.
57. How can weak password complexity policies contribute to authentication bypass?
A) They allow attackers to brute-force weak passwords easily
B) They prevent API attacks
C) They slow down login requests
D) They require additional authentication factors
Answer: A
Explanation: Weak password policies make brute-force and dictionary attacks more successful, allowing attackers to bypass authentication.
58. How can session fixation be prevented?
A) By regenerating session IDs after login
B) By using plaintext password storage
C) By disabling account lockout mechanisms
D) By enforcing weak password policies
Answer: A
Explanation: Regenerating session IDs upon authentication prevents attackers from forcing victims to use known session IDs.
59. What is an “authentication relay attack”?
A) A man-in-the-middle attack that forwards authentication requests to gain access
B) A brute-force attack on login credentials
C) A method of bypassing CAPTCHA challenges
D) A vulnerability that allows XSS attacks
Answer: A
Explanation: In authentication relay attacks, attackers intercept authentication requests and forward them to gain unauthorized access.
60. Why is JSON Web Token (JWT) tampering a serious security risk?
A) Attackers can modify the token payload to escalate privileges
B) It improves authentication security
C) It prevents replay attacks
D) It forces users to reset their passwords
Answer: A
Explanation: If JWTs are not properly signed or verified, attackers can modify the token payload to gain unauthorized access or escalate privileges.
61. How can attackers bypass authentication using a Reflected Cross-Site Scripting (XSS) vulnerability?
A) By injecting malicious JavaScript that steals session tokens
B) By brute-forcing weak passwords
C) By modifying database entries
D) By performing buffer overflow attacks
Answer: A
Explanation: Attackers use reflected XSS to inject JavaScript that steals authentication cookies or session tokens, allowing them to impersonate users.
62. What is the impact of weak “Remember Me” functionality on authentication security?
A) Attackers can steal persistent authentication cookies to bypass login
B) It forces users to enter their passwords more frequently
C) It improves authentication security
D) It prevents brute-force attacks
Answer: A
Explanation: Weak “Remember Me” implementations store authentication tokens insecurely, making them an easy target for theft.
63. Which of the following best prevents authentication bypass due to token reuse?
A) Implementing token expiration and rotation
B) Storing passwords in plaintext
C) Using MD5 for password hashing
D) Disabling CAPTCHA
Answer: A
Explanation: Expiring and rotating authentication tokens frequently prevents attackers from reusing stolen tokens for authentication bypass.
64. How does an HTTP-only flag on cookies improve authentication security?
A) It prevents JavaScript from accessing session cookies
B) It encrypts user passwords
C) It speeds up authentication processes
D) It allows multiple users to share authentication tokens
Answer: A
Explanation: HTTP-only cookies prevent client-side scripts (such as those used in XSS attacks) from accessing authentication tokens.
65. How can attackers exploit weak access control in multi-tenant applications?
A) By accessing unauthorized user data due to improper permission enforcement
B) By brute-forcing API credentials
C) By injecting SQL queries into login forms
D) By modifying firewall settings
Answer: A
Explanation: Weak access control in multi-tenant apps can lead to attackers accessing other tenants’ data if user permissions are not properly enforced.
66. What is an authentication replay attack?
A) Intercepting and reusing a legitimate authentication request
B) Modifying API requests to bypass login
C) Brute-forcing authentication tokens
D) Injecting JavaScript into login pages
Answer: A
Explanation: In a replay attack, attackers capture authentication requests and replay them to gain unauthorized access.
67. What is a credential stuffing attack?
A) Using leaked username-password combinations from data breaches to gain access
B) Injecting malicious JavaScript into login forms
C) Sending brute-force login attempts from multiple locations
D) Modifying firewall rules
Answer: A
Explanation: Credential stuffing automates login attempts using previously breached credentials to exploit password reuse across multiple sites.
68. How does an attacker perform an “Account Takeover Attack”?
A) By gaining unauthorized access to a user’s account through stolen credentials or session hijacking
B) By modifying CAPTCHA settings
C) By sending mass phishing emails without a payload
D) By injecting SQL queries into API requests
Answer: A
Explanation: Account takeover attacks involve credential theft, session hijacking, or exploiting authentication weaknesses to gain control over user accounts.
69. What is the primary reason why multi-factor authentication (MFA) helps prevent authentication bypass?
A) It requires additional verification beyond passwords
B) It encrypts authentication tokens
C) It prevents brute-force attacks
D) It forces users to change their passwords frequently
Answer: A
Explanation: MFA adds a secondary layer of authentication, preventing attackers from gaining access with stolen passwords alone.
70. How can an insecure password reset process lead to authentication bypass?
A) If the reset link or token can be guessed or intercepted
B) If it requires users to answer security questions
C) If it uses strong encryption
D) If it enforces password complexity rules
Answer: A
Explanation: Weak password reset flows allow attackers to guess or intercept reset links, giving them control over user accounts.
71. What is the primary risk of not implementing session expiration?
A) Attackers can reuse old session tokens to gain access
B) Users have to log in more frequently
C) It prevents CAPTCHA bypass
D) It forces users to update their passwords regularly
Answer: A
Explanation: Sessions that do not expire can be reused indefinitely, allowing attackers to hijack them even after logout.
72. What is the purpose of implementing an “Account Lockout Policy”?
A) To prevent brute-force login attempts by locking accounts after multiple failed logins
B) To encrypt user passwords in the database
C) To allow users to bypass authentication in emergencies
D) To prevent session hijacking
Answer: A
Explanation: Account lockout policies stop brute-force attacks by limiting login attempts and temporarily locking accounts after repeated failures.
73. What is a magic link authentication method?
A) A login method that sends a one-time link to a user’s email to authenticate
B) A password recovery tool
C) A CAPTCHA-based authentication method
D) A brute-force prevention mechanism
Answer: A
Explanation: Magic links authenticate users via a unique one-time link sent to their email, reducing reliance on passwords.
74. What is OAuth token forgery?
A) Manipulating OAuth tokens to gain unauthorized access
B) Using OAuth for secure authentication
C) Encrypting user passwords using OAuth
D) Preventing SQL Injection
Answer: A
Explanation: Attackers forge or manipulate OAuth tokens to impersonate users or escalate privileges.
75. How do attackers exploit session fixation vulnerabilities?
A) By forcing a victim to use a predetermined session ID
B) By brute-forcing session tokens
C) By using phishing techniques to steal credentials
D) By injecting JavaScript into login forms
Answer: A
Explanation: In session fixation, attackers set a known session ID for a victim, then hijack it once the user logs in.
76. What is the primary purpose of using HSTS (HTTP Strict Transport Security) in authentication security?
A) To enforce secure HTTPS connections and prevent SSL stripping attacks
B) To prevent brute-force attacks
C) To limit the number of login attempts
D) To disable JavaScript in authentication forms
Answer: A
Explanation: HSTS ensures that all communications occur over HTTPS, preventing attackers from forcing users onto insecure HTTP connections.
77. How does a WebAuthn-based authentication method improve security?
A) It uses biometric and hardware-based authentication instead of passwords
B) It requires users to answer security questions
C) It forces users to change passwords every 30 days
D) It allows passwords to be stored in plaintext
Answer: A
Explanation: WebAuthn replaces passwords with biometrics or security keys, making authentication more secure.
78. How does HTTP Basic Authentication increase the risk of authentication bypass?
A) It transmits credentials in plaintext unless secured by HTTPS
B) It uses strong encryption algorithms
C) It prevents session hijacking
D) It forces users to change passwords regularly
Answer: A
Explanation: HTTP Basic Authentication sends credentials in plaintext unless encrypted by HTTPS, making it vulnerable to interception.
79. What is the main advantage of using biometric authentication over passwords?
A) Biometric data is unique and cannot be easily stolen like passwords
B) It requires frequent updates
C) It eliminates all authentication risks
D) It makes authentication slower
Answer: A
Explanation: Biometrics like fingerprints and facial recognition are unique, making them more secure than passwords.
80. Why is using passkeys (passwordless authentication) considered more secure than traditional passwords?
A) Passkeys use public-key cryptography and eliminate password-related risks
B) They require complex passwords
C) They enforce CAPTCHA verification
D) They store credentials in plaintext
Answer: A
Explanation: Passkeys rely on public-key cryptography, reducing the risks associated with stolen passwords or phishing attacks.
81. What is a “Session Hijacking Attack”?
A) Intercepting an active session to take over a user’s authenticated state
B) Using brute force to guess passwords
C) Injecting malicious JavaScript into login forms
D) Forcing users to change their passwords frequently
Answer: A
Explanation: Session hijacking occurs when an attacker steals a valid session ID to take over a user’s authenticated session.
82. What is the main weakness of using SMS-based two-factor authentication (2FA)?
A) It can be intercepted using SIM swapping attacks
B) It improves security against all attacks
C) It prevents brute force attacks
D) It encrypts authentication data
Answer: A
Explanation: Attackers can perform SIM swapping to receive SMS-based authentication codes and bypass two-factor authentication.
83. What is “Frictionless Authentication”?
A) A security approach that minimizes user interaction during authentication
B) A method of forcing password resets
C) A brute-force protection mechanism
D) A type of SQL Injection attack
Answer: A
Explanation: Frictionless authentication aims to improve security while reducing user friction, often using behavioral analysis and risk-based authentication.
84. What is a key feature of FIDO2 authentication?
A) It eliminates passwords by using biometrics and security keys
B) It forces users to change their passwords regularly
C) It relies on weak password storage
D) It prevents brute-force attacks using captchas
Answer: A
Explanation: FIDO2 provides passwordless authentication using cryptographic keys and biometrics, enhancing security.
85. What is “risk-based authentication”?
A) An authentication approach that adjusts security based on user behavior and risk level
B) A brute-force attack prevention mechanism
C) A method of using weak passwords securely
D) A CAPTCHA-based login system
Answer: A
Explanation: Risk-based authentication adapts security measures based on login behavior, device, location, and risk level.
86. What does “Federated Authentication” mean?
A) Using a single identity provider for multiple applications
B) Requiring multiple authentication methods for login
C) A brute-force prevention system
D) A technique to bypass authentication
Answer: A
Explanation: Federated authentication allows users to log in to multiple systems using a single identity provider, improving security and convenience.
87. How do attackers exploit “Clickjacking” to bypass authentication?
A) By tricking users into clicking on invisible authentication elements
B) By injecting SQL commands into login forms
C) By modifying firewall rules
D) By brute-forcing authentication tokens
Answer: A
Explanation: Clickjacking places transparent authentication elements over malicious pages, tricking users into interacting with them unintentionally.
88. How does an attacker perform “Man-in-the-Browser” (MitB) attacks?
A) By injecting malicious code into a victim’s browser to intercept authentication credentials
B) By brute-forcing passwords
C) By modifying TLS encryption
D) By attacking the DNS server
Answer: A
Explanation: MitB attacks involve malware injecting code into the browser to steal authentication credentials or modify transactions.
89. What is an “Authentication Token Side-Channel Attack”?
A) Exploiting timing differences in token validation to infer authentication secrets
B) Using brute-force attacks on authentication tokens
C) Modifying API requests to bypass login
D) Injecting malicious JavaScript into authentication pages
Answer: A
Explanation: Side-channel attacks exploit timing variations or hardware behavior to extract sensitive authentication data.
90. Why is a “Passwordless Authentication” system considered secure?
A) It eliminates password-based attacks like phishing and credential stuffing
B) It requires long, complex passwords
C) It makes brute-force attacks easier
D) It forces frequent password resets
Answer: A
Explanation: Passwordless authentication removes reliance on passwords, reducing phishing, credential stuffing, and password reuse risks.
91. How does a “Shadow Account Attack” bypass authentication?
A) By creating unauthorized accounts with admin privileges
B) By using stolen session cookies
C) By modifying API requests
D) By injecting malicious JavaScript
Answer: A
Explanation: Shadow accounts are secretly created accounts with admin rights, allowing attackers to gain persistent access.
92. What is a “Backdoor Authentication Bypass”?
A) Gaining unauthorized access using hidden or undocumented authentication mechanisms
B) Performing brute-force attacks on login pages
C) Exploiting weak encryption algorithms
D) Using password spraying attacks
Answer: A
Explanation: Attackers exploit backdoors left in software (intentionally or unintentionally) to bypass authentication.
93. Why are “Shared Credentials” a security risk?
A) Multiple people using the same login increases the risk of leaks and unauthorized access
B) It makes brute-force attacks harder
C) It enhances security by allowing multiple users to verify each login
D) It prevents phishing attacks
Answer: A
Explanation: Shared credentials increase the risk of unauthorized access and credential leaks, making authentication bypass easier.
94. What is an “Email OTP Relay Attack”?
A) Capturing and replaying one-time passwords (OTPs) sent via email
B) Brute-forcing OTP values
C) Encrypting authentication tokens
D) Modifying HTTP request headers
Answer: A
Explanation: Attackers intercept or reuse email OTPs to bypass authentication mechanisms.
95. How do attackers bypass authentication using “Keystroke Injection Attacks”?
A) By injecting malicious keystrokes into a compromised device to enter credentials
B) By brute-forcing login credentials
C) By modifying TLS configurations
D) By intercepting DNS queries
Answer: A
Explanation: Attackers use hardware or software keystroke injection to input malicious commands, potentially bypassing authentication.
96. What is “SSO Token Hijacking”?
A) Stealing and reusing Single Sign-On (SSO) tokens to impersonate users
B) Brute-forcing authentication credentials
C) Injecting SQL queries into authentication forms
D) Modifying HTTP request headers
Answer: A
Explanation: Attackers who steal SSO tokens can authenticate as legitimate users without needing credentials.
97. What is “Precomputed Authentication Bypass”?
A) Using rainbow tables to crack hashed authentication data
B) Guessing weak passwords manually
C) Injecting malicious JavaScript into login pages
D) Modifying API responses
Answer: A
Explanation: Precomputed attacks use techniques like rainbow tables to quickly crack hashed authentication credentials.
98. What is “Implicit Authentication”?
A) An authentication system that analyzes user behavior instead of requiring passwords
B) A type of brute-force attack
C) A way to reset passwords without email verification
D) A method of encrypting authentication data
Answer: A
Explanation: Implicit authentication relies on behavior patterns, device usage, and location instead of passwords.
99. How can attackers exploit “Weak API Rate Limits” for authentication bypass?
A) By sending a high volume of authentication requests without restriction
B) By modifying TLS configurations
C) By intercepting DNS queries
D) By forcing password resets
Answer: A
Explanation: Weak API rate limits allow attackers to brute-force authentication endpoints without restriction.
100. What is “Step-Up Authentication”?
A) An adaptive authentication method that requires additional verification for high-risk actions
B) A type of brute-force attack
C) A method of encrypting authentication tokens
D) A technique to bypass security questions
Answer: A
Explanation: Step-up authentication dynamically increases security based on risk, requiring additional verification for sensitive actions.
101. What is an “Evil Proxy Attack” in authentication bypass?
A) Using a malicious proxy to intercept and steal authentication credentials
B) Using brute force to guess passwords
C) Encrypting login requests for additional security
D) Forcing password resets via social engineering
Answer: A
Explanation: Evil proxy attacks involve setting up a malicious proxy to capture authentication details, including session cookies and tokens.
102. How does a “Weak Encryption Algorithm” contribute to authentication bypass?
A) It allows attackers to decrypt stored credentials easily
B) It makes login processes faster
C) It increases the complexity of authentication tokens
D) It prevents password reuse
Answer: A
Explanation: Weak encryption algorithms (e.g., MD5, SHA-1) can be cracked using brute-force or rainbow table attacks, leading to authentication bypass.
103. What is “Credential Harvesting”?
A) Collecting usernames and passwords through phishing, keylogging, or malware
B) Generating strong passwords for users
C) A method used to prevent brute-force attacks
D) A CAPTCHA-based authentication system
Answer: A
Explanation: Credential harvesting is the process of gathering usernames and passwords from victims through various attack techniques.
104. How can attackers exploit “Time-Based One-Time Passwords (TOTP)”?
A) By stealing the shared secret used to generate OTPs
B) By brute-forcing OTP values
C) By injecting SQL queries into the authentication system
D) By modifying API response headers
Answer: A
Explanation: If an attacker gains access to the TOTP shared secret, they can generate valid OTPs and bypass authentication.
105. What is an “Authorization Bypass Attack”?
A) Gaining access to restricted areas of a system without authentication
B) A method of strengthening authentication systems
C) Encrypting user credentials to prevent data breaches
D) A way to force password resets
Answer: A
Explanation: Authorization bypass occurs when attackers exploit security flaws to access restricted resources without proper authentication.
106. How does an attacker exploit “Insecure Mobile App Authentication”?
A) By reversing and modifying mobile app authentication logic
B) By using long, complex passwords
C) By encrypting API requests
D) By modifying session expiration settings
Answer: A
Explanation: Attackers analyze and modify mobile app authentication processes to bypass security controls.
107. What is “Security Assertion Markup Language (SAML) Token Forgery”?
A) Modifying SAML tokens to impersonate users
B) Encrypting authentication responses for additional security
C) A brute-force attack against SAML authentication
D) Preventing API authentication bypass
Answer: A
Explanation: SAML token forgery allows attackers to manipulate authentication assertions and gain unauthorized access.
108. Why is “Reused Passwords” a major authentication security risk?
A) If a password is leaked in one breach, attackers can use it to access other accounts
B) It prevents brute-force attacks
C) It helps users remember their credentials
D) It makes multi-factor authentication more effective
Answer: A
Explanation: Using the same password across multiple accounts makes it easier for attackers to compromise multiple systems using credential stuffing attacks.
109. What is a “Self-XSS Authentication Bypass”?
A) Tricking a user into running malicious JavaScript in their own browser
B) Using CAPTCHA bypassing techniques
C) Encrypting authentication requests for security
D) Using brute force to guess user credentials
Answer: A
Explanation: Self-XSS tricks users into executing malicious scripts that can steal authentication tokens.
110. What is “Identity Federation Exploitation”?
A) Gaining unauthorized access by manipulating federated authentication systems
B) Using strong multi-factor authentication
C) Preventing SQL Injection in authentication forms
D) Using OAuth tokens for additional security
Answer: A
Explanation: Attackers exploit weaknesses in federated authentication systems (e.g., SAML, OAuth) to impersonate users.
111. How does “Session Replay Attack” bypass authentication?
A) By capturing and replaying legitimate authentication requests
B) By brute-forcing authentication tokens
C) By modifying API request headers
D) By using CAPTCHA bypass techniques
Answer: A
Explanation: In session replay attacks, attackers capture valid authentication requests and resend them to gain unauthorized access.
112. What is “Zombie Session Exploitation”?
A) Using an expired but still-active session to bypass authentication
B) A method to enforce password resets
C) Encrypting authentication data to prevent replay attacks
D) Using machine learning to analyze authentication patterns
Answer: A
Explanation: If a session remains valid after logout or expiration, attackers can reuse it to access accounts.
113. What is “Token Sidejacking”?
A) Intercepting authentication tokens and using them to impersonate users
B) A brute-force attack against authentication systems
C) Encrypting authentication responses for security
D) Using TLS encryption to secure authentication requests
Answer: A
Explanation: Token sidejacking occurs when attackers steal authentication tokens and use them to bypass login mechanisms.
114. How do attackers exploit “Insecure API Authentication”?
A) By sending unauthorized API requests to bypass authentication controls
B) By enforcing strong authentication policies
C) By encrypting API responses
D) By forcing password resets
Answer: A
Explanation: If API authentication is weak or misconfigured, attackers can send requests that bypass authentication and access restricted data.
115. What is “Forced Browsing Attack”?
A) Accessing unauthorized pages by manually entering URLs
B) A method of encrypting login credentials
C) A CAPTCHA-based authentication system
D) Preventing password reuse
Answer: A
Explanation: Forced browsing exploits authentication weaknesses by accessing restricted pages directly without authentication.
116. What is “Account Pre-Hijacking”?
A) Registering an account with a victim’s email before they do and taking control later
B) A method of protecting user credentials
C) A brute-force attack against login pages
D) Encrypting authentication requests
Answer: A
Explanation: Attackers pre-register accounts using a victim’s email and take control once the victim tries to claim the account.
117. What is “Application Logic Bypass”?
A) Exploiting business logic flaws to bypass authentication
B) Encrypting authentication tokens
C) Using brute-force attacks to guess passwords
D) Forcing password resets via social engineering
Answer: A
Explanation: Application logic bypass attacks exploit flaws in authentication workflows to gain unauthorized access.
118. What is “Replay Attack Mitigation”?
A) Implementing nonces and timestamps to prevent authentication replay
B) Using weak password policies
C) Allowing multiple users to share credentials
D) Encrypting authentication tokens with MD5
Answer: A
Explanation: Using nonces and timestamps ensures that authentication requests cannot be reused by attackers.
119. Why is “OAuth Token Expiration” important?
A) It prevents attackers from using stolen tokens indefinitely
B) It makes login processes faster
C) It allows users to use weak passwords securely
D) It forces users to change their passwords
Answer: A
Explanation: Expiring OAuth tokens reduces the risk of authentication bypass through token theft.
120. How does “CAPTCHA Bypass using Machine Learning” work?
A) AI models recognize and solve CAPTCHA challenges automatically
B) Attackers modify firewall settings
C) CAPTCHA tokens are encrypted for security
D) Authentication requests are hashed
Answer: A
Explanation: Attackers use AI and OCR technology to bypass CAPTCHA challenges, allowing automated attacks on login pages.
121. How does a “Man-in-the-Middle (MITM) Attack” help bypass authentication?
A) By intercepting and modifying authentication data in transit
B) By brute-forcing login credentials
C) By encrypting authentication requests
D) By performing CAPTCHA solving
Answer: A
Explanation: MITM attacks allow attackers to eavesdrop on or modify authentication traffic, stealing credentials or session tokens.
122. What is an “Authentication Replay Protection Mechanism”?
A) A security feature that prevents attackers from reusing intercepted authentication requests
B) A method of storing passwords in plaintext
C) A type of CAPTCHA verification
D) A brute-force prevention technique
Answer: A
Explanation: Replay protection uses nonces, timestamps, or session-based tokens to prevent attackers from reusing valid authentication requests.
123. What is an “IP Whitelisting Bypass Attack”?
A) Using VPNs or proxies to spoof allowed IP addresses
B) A method of encrypting authentication requests
C) A brute-force attack on login pages
D) Forcing password resets
Answer: A
Explanation: Attackers bypass IP whitelisting by using VPNs or compromised systems to appear as a trusted source.
124. What is a “DNS Spoofing Attack” in authentication bypass?
A) Redirecting users to a fake authentication page by manipulating DNS records
B) Brute-forcing weak passwords
C) Encrypting authentication tokens
D) Using CAPTCHA to secure authentication
Answer: A
Explanation: DNS spoofing tricks users into visiting malicious sites where their credentials can be stolen.
125. How does an attacker exploit “Insecure WebSockets Authentication”?
A) By hijacking or intercepting WebSocket messages to bypass authentication
B) By performing brute-force attacks
C) By injecting malicious JavaScript into login pages
D) By modifying HTTP headers
Answer: A
Explanation: If WebSockets are not properly secured, attackers can hijack authentication messages and impersonate users.
126. What is a “Forced Password Reset Attack”?
A) Manipulating the password reset process to gain unauthorized access
B) A method of encrypting authentication tokens
C) A brute-force attack against login credentials
D) Using TLS encryption to secure authentication requests
Answer: A
Explanation: Attackers exploit weak password reset mechanisms by hijacking or predicting reset links to take over accounts.
127. What is a “Social Engineering Authentication Bypass”?
A) Tricking users into revealing authentication details via deception
B) A brute-force attack technique
C) Using SQL Injection to modify authentication logic
D) Encrypting authentication responses
Answer: A
Explanation: Attackers use social engineering to manipulate users into providing their authentication credentials.
128. How does “OAuth Scopes Misconfiguration” lead to authentication bypass?
A) If applications grant excessive permissions, attackers can escalate privileges
B) By brute-forcing OAuth tokens
C) By encrypting authentication requests
D) By modifying firewall rules
Answer: A
Explanation: If OAuth scopes are misconfigured, attackers can gain unauthorized access to resources.
129. What is an “Authentication Timeout Attack”?
A) Exploiting sessions that do not expire properly
B) A brute-force attack on login forms
C) Using CAPTCHA bypass techniques
D) Encrypting authentication tokens for security
Answer: A
Explanation: If session timeouts are improperly configured, attackers can reuse expired sessions to bypass authentication.
130. How does an attacker use “Automated Botnets” to bypass authentication?
A) By performing large-scale brute-force attacks across multiple IP addresses
B) By encrypting authentication requests
C) By modifying user passwords without consent
D) By using TLS encryption to prevent attacks
Answer: A
Explanation: Botnets automate brute-force attacks and distribute login attempts to avoid detection.
131. What is an “Attacker-Controlled SAML Response”?
A) Modifying SAML authentication responses to grant unauthorized access
B) Encrypting authentication tokens for security
C) A method of performing a brute-force attack
D) Using CAPTCHA to bypass authentication
Answer: A
Explanation: Attackers modify SAML authentication responses to impersonate users or escalate privileges.
132. What is “Time-of-Check to Time-of-Use (TOCTOU) Attack” in authentication?
A) Exploiting race conditions between authentication checks and resource access
B) A brute-force attack method
C) Encrypting authentication tokens for security
D) Using machine learning to analyze authentication attempts
Answer: A
Explanation: TOCTOU attacks manipulate timing differences between authentication and resource access to bypass security controls.
133. What is a “Brute-Force Authentication Token Attack”?
A) Attempting to guess valid authentication tokens through automation
B) Encrypting authentication tokens for security
C) Using TLS to prevent authentication bypass
D) A method of resetting user passwords
Answer: A
Explanation: Attackers try different authentication tokens until they find a valid one, bypassing login restrictions.
134. How does “Device Fingerprinting Evasion” help bypass authentication?
A) Attackers modify device attributes to appear as a trusted user
B) Encrypting authentication responses for security
C) A brute-force attack method
D) Using OAuth to secure authentication
Answer: A
Explanation: Attackers modify device fingerprints to bypass risk-based authentication and gain unauthorized access.
135. How does an attacker perform “Session Poisoning”?
A) By injecting malicious data into session variables to manipulate authentication
B) By brute-forcing authentication tokens
C) By encrypting login requests
D) By modifying TLS certificates
Answer: A
Explanation: Session poisoning alters session data to bypass authentication or escalate privileges.
136. What is a “Weak Browser Storage Exploit” in authentication?
A) Extracting stored credentials or session tokens from local browser storage
B) A brute-force attack technique
C) Encrypting authentication requests for security
D) Using strong password hashing algorithms
Answer: A
Explanation: If authentication data is stored insecurely in the browser, attackers can extract and reuse it.
137. How does “Unvalidated API Token Usage” lead to authentication bypass?
A) If API tokens are not properly validated, attackers can reuse stolen or expired tokens
B) By brute-forcing login pages
C) By encrypting authentication requests for security
D) By using TLS encryption
Answer: A
Explanation: Attackers exploit weak token validation to authenticate as other users.
138. What is an “Invisible CAPTCHA Bypass”?
A) Using AI or automated scripts to solve CAPTCHA challenges
B) Encrypting authentication responses for security
C) Using OAuth to secure authentication
D) A method of brute-forcing authentication tokens
Answer: A
Explanation: Attackers use machine learning and OCR tools to bypass CAPTCHA challenges.
139. How does “Zero-Day Exploitation” impact authentication security?
A) Attackers exploit unknown authentication vulnerabilities before patches are available
B) Encrypting authentication responses for security
C) A method of brute-forcing authentication tokens
D) Using TLS encryption to prevent attacks
Answer: A
Explanation: Zero-day exploits take advantage of unpatched vulnerabilities to bypass authentication mechanisms.
140. What is a “Push Notification Hijack Attack” in authentication?
A) Intercepting or manipulating push notifications used for 2FA authentication
B) Encrypting authentication responses for security
C) A brute-force attack method
D) Using OAuth to secure authentication
Answer: A
Explanation: Attackers trick users into approving fraudulent push notifications, bypassing two-factor authentication.
141. What is a “Token Impersonation Attack” in authentication bypass?
A) Using stolen or forged authentication tokens to impersonate a legitimate user
B) Encrypting authentication responses for security
C) A brute-force attack method
D) Using OAuth to secure authentication
Answer: A
Explanation: Attackers use stolen or manipulated tokens to authenticate as other users without knowing their credentials.
142. What is “Weak Password Hashing Exploitation”?
A) Cracking weakly hashed passwords using rainbow tables or brute force
B) Encrypting authentication responses for security
C) A brute-force attack method
D) Using CAPTCHA to prevent brute-force attacks
Answer: A
Explanation: Weak hashing algorithms (e.g., MD5, SHA-1) are vulnerable to cracking, allowing attackers to retrieve plaintext passwords.
143. How do attackers exploit “Insecure OAuth Redirects”?
A) By redirecting users to malicious login pages to steal credentials
B) Encrypting authentication responses for security
C) A brute-force attack method
D) Using strong multi-factor authentication
Answer: A
Explanation: Attackers exploit OAuth misconfigurations by redirecting users to malicious websites that capture authentication credentials.
144. What is a “Fake Login Portal Attack”?
A) Creating a fraudulent login page to steal credentials
B) Encrypting authentication responses for security
C) A brute-force attack method
D) Using strong password hashing
Answer: A
Explanation: Attackers set up fake login portals to harvest user credentials and bypass authentication.
145. How does an attacker exploit “Publicly Accessible Debug Panels” for authentication bypass?
A) By using exposed debug panels to execute admin commands without authentication
B) Encrypting authentication responses for security
C) A brute-force attack method
D) Using TLS encryption
Answer: A
Explanation: If debug panels are publicly accessible and lack authentication, attackers can exploit them to manipulate user sessions.
146. How does “Session Expiration Misconfiguration” lead to authentication bypass?
A) If expired sessions remain active, attackers can reuse them to gain access
B) Encrypting authentication responses for security
C) A brute-force attack method
D) Using OAuth to secure authentication
Answer: A
Explanation: Proper session expiration prevents attackers from using old sessions to bypass authentication.
147. What is an “Account Enumeration Attack”?
A) Identifying valid usernames through error messages or timing differences
B) Encrypting authentication responses for security
C) A brute-force attack method
D) Using strong multi-factor authentication
Answer: A
Explanation: Attackers exploit inconsistencies in login responses to determine valid usernames for further attacks.
148. How do attackers exploit “Insecure API Key Management”?
A) By using exposed or leaked API keys to authenticate as other users
B) Encrypting authentication responses for security
C) A brute-force attack method
D) Using OAuth to secure authentication
Answer: A
Explanation: If API keys are stored insecurely or leaked, attackers can use them to bypass authentication.
149. What is “Privilege Escalation via Authentication Bypass”?
A) Exploiting authentication flaws to gain higher privileges
B) Encrypting authentication responses for security
C) A brute-force attack method
D) Using TLS encryption
Answer: A
Explanation: Attackers exploit authentication weaknesses to escalate their privileges within an application.
150. What is “Insufficient Session Binding” in authentication security?
A) When authentication tokens are not tied to user-specific attributes, allowing reuse
B) Encrypting authentication responses for security
C) A brute-force attack method
D) Using OAuth to secure authentication
Answer: A
Explanation: Proper session binding ensures that authentication tokens cannot be reused by other users or devices.
151. How does an attacker exploit “Weak Captcha Implementation”?
A) By using automated scripts or AI to solve CAPTCHA challenges
B) Encrypting authentication responses for security
C) A brute-force attack method
D) Using strong multi-factor authentication
Answer: A
Explanation: Attackers use machine learning or CAPTCHA farms to bypass CAPTCHA-based authentication mechanisms.
152. What is “Zero Trust Authentication”?
A) A security model that continuously verifies user identity rather than assuming trust
B) A method of brute-forcing authentication credentials
C) Encrypting authentication responses for security
D) Using weak password policies
Answer: A
Explanation: Zero Trust security requires continuous identity verification, reducing authentication bypass risks.
153. How does an attacker exploit “Unvalidated JWT Signatures”?
A) By altering JWT payloads if the application does not validate the signature
B) Encrypting authentication responses for security
C) A brute-force attack method
D) Using TLS encryption
Answer: A
Explanation: If JWT signatures are not properly validated, attackers can forge authentication tokens.
154. What is “Authentication Downgrade Attack”?
A) Forcing a system to use a weaker authentication method
B) Encrypting authentication responses for security
C) A brute-force attack method
D) Using OAuth to secure authentication
Answer: A
Explanation: Attackers force systems to downgrade to weaker authentication methods to bypass security controls.
155. How does “Insecure Password Storage” contribute to authentication bypass?
A) Attackers can retrieve plaintext or weakly hashed passwords and use them for access
B) Encrypting authentication responses for security
C) A brute-force attack method
D) Using TLS encryption
Answer: A
Explanation: Weak password storage enables attackers to recover passwords and bypass authentication.
156. What is “Server-Side Request Forgery (SSRF) in Authentication”?
A) Exploiting server-side requests to access internal authentication mechanisms
B) Encrypting authentication responses for security
C) A brute-force attack method
D) Using OAuth to secure authentication
Answer: A
Explanation: SSRF allows attackers to manipulate server-side requests to access authentication endpoints.
157. How does “Unsecured Biometric Authentication” lead to bypass?
A) If biometric data is stored or transmitted insecurely, it can be intercepted or spoofed
B) Encrypting authentication responses for security
C) A brute-force attack method
D) Using OAuth to secure authentication
Answer: A
Explanation: If biometric data is not properly protected, attackers can use spoofing techniques to bypass authentication.
158. What is “Click-to-Login Exploit” in authentication bypass?
A) Exploiting login links that authenticate users without additional verification
B) Encrypting authentication responses for security
C) A brute-force attack method
D) Using TLS encryption
Answer: A
Explanation: If a login link automatically logs in users without verification, attackers can exploit it to bypass authentication.
159. How does “Cross-Site Script Inclusion (XSSI)” affect authentication security?
A) By tricking a victim’s browser into leaking authentication tokens
B) Encrypting authentication responses for security
C) A brute-force attack method
D) Using OAuth to secure authentication
Answer: A
Explanation: XSSI attacks manipulate authentication responses to expose sensitive user data.
160. How does “Publicly Exposed Private Keys” impact authentication security?
A) Attackers can use leaked private keys to decrypt authentication data and forge credentials
B) Encrypting authentication responses for security
C) A brute-force attack method
D) Using TLS encryption
Answer: A
Explanation: If private keys are exposed, attackers can decrypt authentication data and forge credentials to bypass authentication.
161. What is “TLS Stripping” in authentication bypass?
A) Downgrading HTTPS to HTTP to intercept plaintext authentication credentials
B) Encrypting authentication responses for security
C) A brute-force attack on login pages
D) Using CAPTCHA to prevent automated attacks
Answer: A
Explanation: TLS stripping downgrades encrypted HTTPS connections to HTTP, allowing attackers to intercept login credentials in plaintext.
162. How does “Subdomain Takeover” lead to authentication bypass?
A) Attackers gain control of an abandoned subdomain and impersonate login pages
B) Encrypting authentication tokens to improve security
C) A brute-force attack against subdomain records
D) Using OAuth tokens to secure authentication
Answer: A
Explanation: If a subdomain used for authentication is abandoned, attackers can take control and use it for phishing or session hijacking.
163. What is “Broken Object-Level Authorization (BOLA)” in authentication security?
A) Allowing unauthorized access to resources by manipulating object identifiers
B) Encrypting authentication responses for security
C) A brute-force attack on login credentials
D) Using CAPTCHA to prevent attacks
Answer: A
Explanation: BOLA vulnerabilities allow attackers to access other users’ data by modifying object references in API requests.
164. How do attackers exploit “DNS Rebinding” to bypass authentication?
A) By tricking a victim’s browser into communicating with unauthorized internal resources
B) Encrypting authentication responses for security
C) A brute-force attack on authentication tokens
D) Using CAPTCHA bypass techniques
Answer: A
Explanation: DNS rebinding manipulates domain resolution to bypass same-origin policy, allowing attackers to access internal services.
165. What is a “Client-Side Token Tampering Attack”?
A) Modifying authentication tokens stored in local storage or cookies
B) Encrypting authentication responses for security
C) A brute-force attack against JWTs
D) Using OAuth to secure authentication
Answer: A
Explanation: If authentication tokens are stored insecurely on the client side, attackers can modify them to bypass authentication.
166. What is an “Account Lockout Bypass Attack”?
A) Using various IPs or user agents to bypass failed login attempt limits
B) Encrypting authentication responses for security
C) A brute-force attack on authentication credentials
D) Using CAPTCHA to prevent attacks
Answer: A
Explanation: Attackers bypass account lockout mechanisms by rotating IP addresses, user agents, or using distributed botnets.
167. How does “Forced Authentication via SMB Relay” work?
A) Exploiting Windows SMB authentication to relay credentials for unauthorized access
B) Encrypting authentication responses for security
C) A brute-force attack against Windows login
D) Using OAuth to secure authentication
Answer: A
Explanation: SMB relay attacks capture NTLM authentication requests and relay them to a target system to gain unauthorized access.
168. What is “Padding Oracle Attack” in authentication security?
A) Exploiting padding errors in cryptographic systems to decrypt authentication tokens
B) Encrypting authentication responses for security
C) A brute-force attack against password hashes
D) Using CAPTCHA to prevent attacks
Answer: A
Explanation: Padding oracle attacks exploit cryptographic weaknesses to decrypt sensitive authentication data.
169. How does “User-Agent Spoofing” assist in authentication bypass?
A) Modifying the User-Agent string to bypass device-based authentication restrictions
B) Encrypting authentication responses for security
C) A brute-force attack on login credentials
D) Using OAuth tokens to secure authentication
Answer: A
Explanation: User-Agent spoofing tricks authentication systems into treating an attacker’s device as a trusted one.
170. What is a “MitM Credential Injection Attack”?
A) Injecting malicious credentials into intercepted authentication requests
B) Encrypting authentication responses for security
C) A brute-force attack on login pages
D) Using CAPTCHA to prevent automated attacks
Answer: A
Explanation: Attackers intercept and modify authentication requests to inject their own credentials and gain unauthorized access.
171. What is an “Authentication Bypass via HTTP Header Injection”?
A) Manipulating authentication headers like X-Forwarded-For to spoof identity
B) Encrypting authentication responses for security
C) A brute-force attack against API authentication
D) Using OAuth tokens to secure authentication
Answer: A
Explanation: HTTP header injection exploits improperly validated headers to bypass authentication mechanisms.
172. What is “Device ID Tampering” in authentication security?
A) Modifying a device’s identifier to bypass device-based authentication restrictions
B) Encrypting authentication responses for security
C) A brute-force attack against session tokens
D) Using OAuth tokens to secure authentication
Answer: A
Explanation: Device ID tampering allows attackers to bypass security measures that rely on unique device identification.
173. How does “OAuth Token Replay Attack” work?
A) Reusing a valid OAuth token to gain unauthorized access
B) Encrypting authentication responses for security
C) A brute-force attack against OAuth authentication
D) Using CAPTCHA to prevent attacks
Answer: A
Explanation: If OAuth tokens are not properly validated or expired, attackers can reuse them to bypass authentication.
174. How does “Unencrypted Cookie Theft” lead to authentication bypass?
A) Attackers can steal and reuse unencrypted authentication cookies
B) Encrypting authentication responses for security
C) A brute-force attack against session IDs
D) Using OAuth tokens to secure authentication
Answer: A
Explanation: If authentication cookies are not encrypted, attackers can steal and use them to access accounts.
175. What is an “Authentication Injection Attack”?
A) Injecting malicious input into authentication mechanisms to bypass login restrictions
B) Encrypting authentication responses for security
C) A brute-force attack against login credentials
D) Using OAuth tokens to secure authentication
Answer: A
Explanation: Authentication injection exploits flaws in input validation to manipulate login authentication.
176. What is “Cross-Origin Authentication Token Theft”?
A) Exploiting CORS misconfigurations to steal authentication tokens from another domain
B) Encrypting authentication responses for security
C) A brute-force attack against login credentials
D) Using OAuth tokens to secure authentication
Answer: A
Explanation: If CORS policies are misconfigured, attackers can extract authentication tokens from cross-origin requests.
177. What is “IDN Homograph Attack” in authentication bypass?
A) Using visually similar domain names to trick users into entering credentials
B) Encrypting authentication responses for security
C) A brute-force attack against login credentials
D) Using OAuth tokens to secure authentication
Answer: A
Explanation: Attackers register domain names that visually resemble legitimate ones to steal user credentials.
178. How does “Fake OTP Bypass” work in authentication security?
A) Trick users into entering their OTPs on attacker-controlled sites
B) Encrypting authentication responses for security
C) A brute-force attack against OTP mechanisms
D) Using OAuth tokens to secure authentication
Answer: A
Explanation: Attackers use phishing or social engineering to trick victims into providing one-time passwords.
179. What is “Partial Token Disclosure Attack”?
A) Extracting partial authentication tokens and reconstructing them for access
B) Encrypting authentication responses for security
C) A brute-force attack against login credentials
D) Using OAuth tokens to secure authentication
Answer: A
Explanation: If parts of authentication tokens are leaked, attackers can reconstruct them to bypass security.
180. How does “Weak MFA Recovery Mechanism” lead to authentication bypass?
A) If recovery options are weak, attackers can reset MFA and bypass authentication
B) Encrypting authentication responses for security
C) A brute-force attack against MFA codes
D) Using OAuth tokens to secure authentication
Answer: A
Explanation: If attackers exploit weak recovery mechanisms, they can reset MFA and gain unauthorized access.
181. How does “Malicious Browser Extensions” contribute to authentication bypass?
A) By stealing session cookies and login credentials from users’ browsers
B) Encrypting authentication responses for security
C) A brute-force attack against authentication forms
D) Using OAuth tokens to secure authentication
Answer: A
Explanation: Malicious browser extensions can access cookies, session tokens, and form inputs, allowing attackers to hijack authenticated sessions.
182. What is “Authentication Bypass via Client-Side API Modification”?
A) Manipulating JavaScript authentication checks in web applications to gain access
B) Encrypting authentication responses for security
C) A brute-force attack against login credentials
D) Using OAuth tokens to secure authentication
Answer: A
Explanation: If authentication logic is enforced only on the client side, attackers can modify scripts to bypass security controls.
183. What is “Hidden Form Field Manipulation” in authentication bypass?
A) Modifying hidden authentication fields in HTML to escalate privileges
B) Encrypting authentication responses for security
C) A brute-force attack against login forms
D) Using OAuth tokens to secure authentication
Answer: A
Explanation: Attackers modify hidden form fields, such as user roles or authentication tokens, to bypass login restrictions.
184. How does “Privilege Escalation via Password Reset Exploits” work?
A) Manipulating password reset flows to escalate privileges
B) Encrypting authentication responses for security
C) A brute-force attack against password recovery mechanisms
D) Using OAuth tokens to secure authentication
Answer: A
Explanation: Attackers exploit password reset functionality to gain administrative or unauthorized access.
185. How do attackers use “Browser Autofill Exploits” to bypass authentication?
A) By tricking browsers into auto-filling stored credentials on malicious pages
B) Encrypting authentication responses for security
C) A brute-force attack against session tokens
D) Using OAuth tokens to secure authentication
Answer: A
Explanation: If autofill settings are enabled, attackers can trick users into revealing their credentials on hidden form fields.
186. What is “Authentication Bypass via Code Injection in Mobile Apps”?
A) Injecting malicious code into a mobile app to disable authentication checks
B) Encrypting authentication responses for security
C) A brute-force attack against mobile authentication
D) Using OAuth tokens to secure authentication
Answer: A
Explanation: Attackers modify mobile app code to disable authentication mechanisms and gain unauthorized access.
187. How does “Email Address Enumeration” help in authentication bypass?
A) Identifying registered email addresses to target with phishing or brute-force attacks
B) Encrypting authentication responses for security
C) A brute-force attack against email authentication
D) Using OAuth tokens to secure authentication
Answer: A
Explanation: If an application reveals whether an email is registered, attackers can use this information for targeted attacks.
188. What is “Session Key Reuse Attack” in authentication bypass?
A) Exploiting session keys that do not expire or are reused across logins
B) Encrypting authentication responses for security
C) A brute-force attack against session management
D) Using OAuth tokens to secure authentication
Answer: A
Explanation: If session keys remain valid for an extended period, attackers can reuse them to bypass authentication.
189. How does “Predictable Temporary Passwords” lead to authentication bypass?
A) If temporary passwords follow a predictable pattern, attackers can guess them to log in
B) Encrypting authentication responses for security
C) A brute-force attack against temporary passwords
D) Using OAuth tokens to secure authentication
Answer: A
Explanation: Weakly generated temporary passwords (e.g., 123456, password1) can be easily guessed, leading to unauthorized access.
190. What is “Cross-Tenant Authentication Bypass” in cloud environments?
A) Exploiting misconfigurations to access resources in other tenants
B) Encrypting authentication responses for security
C) A brute-force attack against cloud authentication
D) Using OAuth tokens to secure authentication
Answer: A
Explanation: If multi-tenant cloud applications are misconfigured, attackers can access data from other tenants.
191. How does “Abusing Backup Authentication Methods” lead to authentication bypass?
A) Exploiting weaker secondary authentication mechanisms, such as backup codes
B) Encrypting authentication responses for security
C) A brute-force attack against backup authentication
D) Using OAuth tokens to secure authentication
Answer: A
Explanation: If backup authentication options (e.g., backup codes, security questions) are weak, attackers can bypass strong primary authentication.
192. What is “Bypassing Biometric Authentication via Replay Attacks”?
A) Using recorded biometric data (e.g., fingerprints, face scans) to authenticate
B) Encrypting authentication responses for security
C) A brute-force attack against biometric authentication
D) Using OAuth tokens to secure authentication
Answer: A
Explanation: If biometric data is not properly secured, attackers can replay recorded biometric inputs to bypass authentication.
193. How does “Compromising Security Questions” enable authentication bypass?
A) Attackers can guess or research answers to weak security questions
B) Encrypting authentication responses for security
C) A brute-force attack against security questions
D) Using OAuth tokens to secure authentication
Answer: A
Explanation: Security questions often rely on publicly available or easily guessable information.
194. What is “Bypassing Authentication via SIM Cloning”?
A) Duplicating a victim’s SIM card to receive authentication codes
B) Encrypting authentication responses for security
C) A brute-force attack against mobile authentication
D) Using OAuth tokens to secure authentication
Answer: A
Explanation: SIM cloning allows attackers to receive SMS-based authentication codes and bypass login security.
195. How do attackers use “JavaScript Injection in Login Forms” for authentication bypass?
A) Injecting scripts to steal credentials or modify authentication responses
B) Encrypting authentication responses for security
C) A brute-force attack against login forms
D) Using OAuth tokens to secure authentication
Answer: A
Explanation: JavaScript injection can steal user credentials or modify login logic.
196. How does “Bypassing Device-Based Authentication via Emulator Detection Evasion” work?
A) Using modified emulators to bypass device authentication restrictions
B) Encrypting authentication responses for security
C) A brute-force attack against device authentication
D) Using OAuth tokens to secure authentication
Answer: A
Explanation: Some applications restrict access based on device fingerprinting, but attackers can modify emulators to bypass these restrictions.
197. What is “Credential Exfiltration via Browser DevTools”?
A) Extracting authentication tokens and credentials using browser developer tools
B) Encrypting authentication responses for security
C) A brute-force attack against login credentials
D) Using OAuth tokens to secure authentication
Answer: A
Explanation: Attackers use browser DevTools to inspect and extract sensitive authentication data stored in local storage or session cookies.
198. How does “Network Traffic Sniffing on Public Wi-Fi” contribute to authentication bypass?
A) Capturing authentication credentials transmitted over unencrypted connections
B) Encrypting authentication responses for security
C) A brute-force attack against network authentication
D) Using OAuth tokens to secure authentication
Answer: A
Explanation: Attackers on public Wi-Fi can use sniffing tools to capture login credentials if connections are not encrypted.
199. What is “Authentication Bypass via Exploiting Cookie Scope”?
A) Manipulating cookie attributes to access authentication tokens across different subdomains
B) Encrypting authentication responses for security
C) A brute-force attack against cookie authentication
D) Using OAuth tokens to secure authentication
Answer: A
Explanation: If cookie attributes are misconfigured, attackers can use them to gain access across multiple subdomains.
200. How do attackers exploit “Weak HMAC Secret Keys” in authentication?
A) By cracking weak HMAC keys to forge authentication tokens
B) Encrypting authentication responses for security
C) A brute-force attack against JWTs
D) Using OAuth tokens to secure authentication
Answer: A
Explanation: If HMAC keys are weak or guessable, attackers can forge authentication tokens and bypass login security.