OWASP Testing Guide
  • Foreword by Eoin Keary
  • Frontispiece
  • Introduction
  • The OWASP Testing Framework
    • The Web Security Testing Framework
    • Penetration Testing Methodologies
  • Web Application Security Testing
    • Introduction and Objectives
    • Information Gathering
      • Conduct Search Engine Discovery Reconnaissance for Information Leakage (WSTG-INFO-01)
      • Fingerprint Web Server (WSTG-INFO-02)
      • Review Webserver Metafiles for Information Leakage (WSTG-INFO-03)
      • Enumerate Applications on Webserver (WSTG-INFO-04)
      • Review Webpage Content for Information Leakage (WSTG-INFO-05)
      • Identify Application Entry Points (WSTG-INFO-06)
      • Map Execution Paths Through Application (WSTG-INFO-07)
      • Fingerprint Web Application Framework (WSTG-INFO-08)
      • Fingerprint Web Application (WSTG-INFO-09)
      • Map Application Architecture (WSTG-INFO-10)
    • Configuration and Deployment Management Testing
      • Test Network Infrastructure Configuration (WSTG-CONF-01)
      • Test Application Platform Configuration (WSTG-CONF-02)
      • Test File Extensions Handling for Sensitive Information (WSTG-CONF-03)
      • Review Old Backup and Unreferenced Files for Sensitive Information (WSTG-CONF-04)
      • Enumerate Infrastructure and Application Admin Interfaces (WSTG-CONF-05)
      • Test HTTP Methods (WSTG-CONF-06)
      • Test HTTP Strict Transport Security (WSTG-CONF-07)
      • Test RIA Cross Domain Policy (WSTG-CONF-08)
      • Test File Permission (WSTG-CONF-09)
      • Test for Subdomain Takeover (WSTG-CONF-10)
      • Test Cloud Storage (WSTG-CONF-11)
      • Testing for Content Security Policy (WSTG-CONF-12)
    • Identity Management Testing
      • Test Role Definitions (WSTG-IDNT-01)
      • Test User Registration Process (WSTG-IDNT-02)
      • Test Account Provisioning Process (WSTG-IDNT-03)
      • Testing for Account Enumeration and Guessable User Account (WSTG-IDNT-04)
      • Testing for Weak or Unenforced Username Policy (WSTG-IDNT-05)
    • Authentication Testing
      • Testing for Credentials Transported over an Encrypted Channel (WSTG-ATHN-01)
      • Testing for Default Credentials (WSTG-ATHN-02)
      • Testing for Weak Lock Out Mechanism (WSTG-ATHN-03)
      • Testing for Bypassing Authentication Schema (WSTG-ATHN-04)
      • Testing for Vulnerable Remember Password (WSTG-ATHN-05)
      • Testing for Browser Cache Weaknesses (WSTG-ATHN-06)
      • Testing for Weak Password Policy (WSTG-ATHN-07)
      • Testing for Weak Security Question Answer (WSTG-ATHN-08)
      • Testing for Weak Password Change or Reset Functionalities (WSTG-ATHN-09)
      • Testing for Weaker Authentication in Alternative Channel (WSTG-ATHN-10)
      • Testing Multi-Factor Authentication (MFA) (WSTG-AUTH-11)
    • Authorization Testing
      • Testing Directory Traversal File Include (WSTG-ATHZ-01)
      • Testing for Bypassing Authorization Schema (WSTG-ATHZ-02)
      • Testing for Privilege Escalation (WSTG-ATHZ-03)
      • Testing for Insecure Direct Object References (WSTG-ATHZ-04)
      • Testing for OAuth Authorization Server Weaknesses
      • Testing for OAuth Client Weaknesses
      • Testing for OAuth Weaknesses (WSTG-ATHZ-05)
    • Session Management Testing
      • Testing for Session Management Schema (WSTG-SESS-01)
      • Testing for Cookies Attributes (WSTG-SESS-02)
      • Testing for Session Fixation (WSTG-SESS-03)
      • Testing for Exposed Session Variables (WSTG-SESS-04)
      • Testing for Cross Site Request Forgery (WSTG-SESS-05)
      • Testing for Logout Functionality (WSTG-SESS-06)
      • Testing Session Timeout (WSTG-SESS-07)
      • Testing for Session Puzzling (WSTG-SESS-08)
      • Testing for Session Hijacking (WSTG-SESS-09)
      • Testing JSON Web Tokens (WSTG-SESS-10)
    • Input Validation Testing
      • Testing for Reflected Cross Site Scripting (WSTG-INPV-01)
      • Testing for Stored Cross Site Scripting (WSTG-INPV-02)
      • Testing for HTTP Verb Tampering (WSTG-INPV-03)
      • Testing for HTTP Parameter Pollution (WSTG-INPV-04)
      • Testing for Oracle
      • Testing for MySQL
      • Testing for SQL Server
      • Testing PostgreSQL
      • Testing for MS Access
      • Testing for NoSQL Injection
      • Testing for ORM Injection
      • Testing for Client-side
      • Testing for SQL Injection (WSTG-INPV-05)
      • Testing for LDAP Injection (WSTG-INPV-06)
      • Testing for XML Injection (WSTG-INPV-07)
      • Testing for SSI Injection (WSTG-INPV-08)
      • Testing for XPath Injection (WSTG-INPV-09)
      • Testing for IMAP SMTP Injection (WSTG-INPV-10)
      • Testing for File Inclusion
      • Testing for Code Injection (WSTG-INPV-11)
      • Testing for Command Injection (WSTG-INPV-12)
      • Testing for Buffer Overflow (WSTG-INPV-13)
      • Testing for Format String Injection (WSTG-INPV-13)
      • Testing for Incubated Vulnerability (WSTG-INPV-14)
      • Testing for HTTP Splitting Smuggling (WSTG-INPV-15)
      • Testing for HTTP Incoming Requests (WSTG-INPV-16)
      • Testing for Host Header Injection (WSTG-INPV-17)
      • Testing for Server-side Template Injection (WSTG-INPV-18)
      • Testing for Server-Side Request Forgery (WSTG-INPV-19)
      • Testing for Mass Assignment (WSTG-INPV-20)
    • Testing for Error Handling
      • Testing for Improper Error Handling (WSTG-ERRH-01)
      • Testing for Stack Traces (WSTG-ERRH-02)
    • Testing for Weak Cryptography
      • Testing for Weak Transport Layer Security (WSTG-CRYP-01)
      • Testing for Padding Oracle (WSTG-CRYP-02)
      • Testing for Sensitive Information Sent via Unencrypted Channels (WSTG-CRYP-03)
      • Testing for Weak Encryption (WSTG-CRYP-04)
    • Business Logic Testing
      • Introduction to Business Logic
      • Test Business Logic Data Validation (WSTG-BUSL-01)
      • Test Ability to Forge Requests (WSTG-BUSL-02)
      • Test Integrity Checks (WSTG-BUSL-03)
      • Test for Process Timing (WSTG-BUSL-04)
      • Test Number of Times a Function Can Be Used Limits (WSTG-BUSL-05)
      • Testing for the Circumvention of Work Flows (WSTG-BUSL-06)
      • Test Defenses Against Application Misuse (WSTG-BUSL-07)
      • Test Upload of Unexpected File Types (WSTG-BUSL-08)
      • Test Upload of Malicious Files (WSTG-BUSL-09)
      • Test Payment Functionality (WSTG-BUSL-10)
    • Client-Side Testing
      • Testing for Self DOM Based Cross-Site Scripting
      • Testing for DOM-Based Cross Site Scripting (WSTG-CLNT-01)
      • Testing for JavaScript Execution (WSTG-CLNT-02)
      • Testing for HTML Injection (WSTG-CLNT-03)
      • Testing for Client-side URL Redirect (WSTG-CLNT-04)
      • Testing for CSS Injection (WSTG-CLNT-05)
      • Testing for Client-side Resource Manipulation (WSTG-CLNT-06)
      • Testing Cross Origin Resource Sharing (WSTG-CLNT-07)
      • Testing for Cross Site Flashing (WSTG-CLNT-08)
      • Testing for Clickjacking (WSTG-CLNT-09)
      • Testing WebSockets (WSTG-CLNT-10)
      • Testing Web Messaging (WSTG-CLNT-11)
      • Testing Browser Storage (WSTG-CLNT-12)
      • Testing for Cross Site Script Inclusion (WSTG-CLNT-13)
      • Testing for Reverse Tabnabbing (WSTG-CLNT-14)
    • API Testing
      • Testing GraphQL (WSTG-APIT-01)
  • Reporting
    • Reporting
    • Vulnerability Naming Schemes
  • Appendix
    • Testing Tools Resource
    • Suggested Reading
    • Fuzz Vectors
    • Encoded Injection
    • History
    • Leveraging Dev Tools
  • Testing Checklist
  • Table of Contents
  • REST Assessment Cheat Sheet
  • API Testing
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On this page
  • Summary
  • Pre-generated Questions
  • Self-generated Questions
  • Test Objectives
  • How to Test
  • Testing for Weak Pre-generated Questions
  • Testing for Weak Self-Generated Questions
  • Testing for Brute-forcible Answers
  • References
  1. Web Application Security Testing
  2. Authentication Testing

Testing for Weak Security Question Answer (WSTG-ATHN-08)

PreviousTesting for Weak Password Policy (WSTG-ATHN-07)NextTesting for Weak Password Change or Reset Functionalities (WSTG-ATHN-09)

Last updated 2 years ago

ID

WSTG-ATHN-08

Summary

Often called "secret" questions and answers, security questions and answers are often used to recover forgotten passwords (see , or as extra security on top of the password.

They are typically generated upon account creation and require the user to select from some pre-generated questions and supply an appropriate answer. They may allow the user to generate their own question and answer pairs. Both methods are prone to insecurities.Ideally, security questions should generate answers that are only known by the user, and not guessable or discoverable by anybody else. This is harder than it sounds. Security questions and answers rely on the secrecy of the answer. Questions and answers should be chosen so that the answers are only known by the account holder. However, although a lot of answers may not be publicly known, most of the questions that websites implement promote answers that are pseudo-private.

Pre-generated Questions

The majority of pre-generated questions are fairly simplistic in nature and can lead to insecure answers. For example:

  • The answers may be known to family members or close friends of the user, e.g. "What is your mother's maiden name?", "What is your date of birth?"

  • The answers may be easily guessable, e.g. "What is your favorite color?", "What is your favorite baseball team?"

  • The answers may be brute forcible, e.g. "What is the first name of your favorite high school teacher?" - the answer is probably on some easily downloadable lists of popular first names, and therefore a simple brute force attack can be scripted.

  • The answers may be publicly discoverable, e.g. "What is your favorite movie?" - the answer may easily be found on the user's social media profile page.

Self-generated Questions

The problem with having users to generate their own questions is that it allows them to generate very insecure questions, or even bypass the whole point of having a security question in the first place. Here are some real world examples that illustrate this point:

  • "What is 1+1?"

  • "What is your username?"

  • "My password is S3curIty!"

Test Objectives

  • Determine the complexity and how straight-forward the questions are.

  • Assess possible user answers and brute force capabilities.

How to Test

Testing for Weak Pre-generated Questions

Try to obtain a list of security questions by creating a new account or by following the "I don’t remember my password"-process. Try to generate as many questions as possible to get a good idea of the type of security questions that are asked. If any of the security questions fall in the categories described above, they are vulnerable to being attacked (guessed, brute-forced, available on social media, etc.).

Testing for Weak Self-Generated Questions

Testing for Brute-forcible Answers

The first thing to take into consideration when trying to exploit security questions is the number of questions that need to be answered. The majority of applications only need the user to answer a single question, whereas some critical applications may require the user to answer two or even more questions.

The next step is to assess the strength of the security questions. Could the answers be obtained by a simple Google search or with social engineering attack? As a penetration tester, here is a step-by-step walkthrough of exploiting a security question scheme:

  • Does the application allow the end user to choose the question that needs to be answered? If so, focus on questions which have:

    • A "public" answer; for example, something that could be find with a simple search-engine query.

    • A factual answer such as a "first school" or other facts which can be looked up.

    • Few possible answers, such as "what model was your first car". These questions would present the attacker with a short list of possible answers, and based on statistics the attacker could rank answers from most to least likely.

  • Determine how many guesses you have if possible.

    • Does the password reset allow unlimited attempts?

    • Is there a lockout period after X incorrect answers? Keep in mind that a lockout system can be a security problem in itself, as it can be exploited by an attacker to launch a Denial of Service against legitimate users.

    • Pick the appropriate question based on analysis from the above points, and do research to determine the most likely answers.

The key to successfully exploiting and bypassing a weak security question scheme is to find a question or set of questions which give the possibility of easily finding the answers. Always look for questions which can give you the greatest statistical chance of guessing the correct answer, if you are completely unsure of any of the answers. In the end, a security question scheme is only as strong as the weakest question.

References

Try to create security questions by creating a new account or by configuring your existing account’s password recovery properties. If the system allows the user to generate their own security questions, it is vulnerable to having insecure questions created. If the system uses the self-generated security questions during the forgotten password functionality and if usernames can be enumerated (see , then it should be easy for the tester to enumerate a number of self-generated questions. It should be expected to find several weak self-generated questions using this method.

Use the methods described in to determine if a number of incorrectly supplied security answers trigger a lockout mechanism.

Testing for weak password change or reset functionalities
Testing for Account Enumeration and Guessable User Account
Testing for Weak lock out mechanism
The Curse of the Secret Question
The OWASP Security Questions Cheat Sheet