CVE-2021-32641
📋 TL;DR
CVE-2021-32641 is a reflected cross-site scripting (XSS) vulnerability in Auth0's Lock authentication widget. Attackers can inject malicious scripts via URL parameters that get incorporated into flash messages or language dictionaries, potentially stealing user credentials or session tokens. Organizations using Auth0 Lock versions 11.30.0 or earlier for authentication are affected.
💻 Affected Systems
- Auth0 Lock
📦 What is this software?
Lock by Auth0
⚠️ Risk & Real-World Impact
Worst Case
Attackers steal authentication tokens, compromise user accounts, perform account takeover, and potentially pivot to internal systems if users have elevated privileges.
Likely Case
Attackers steal session cookies or authentication tokens from users, leading to account compromise and potential data theft.
If Mitigated
With proper input validation and output encoding, malicious scripts are neutralized, preventing code execution.
🎯 Exploit Status
XSS vulnerabilities are commonly weaponized. The advisory includes technical details that could be used to create exploits.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 11.30.1
Vendor Advisory: https://github.com/auth0/lock/security/advisories/GHSA-jr3j-whm4-9wwm
Restart Required: No
Instructions:
1. Update Auth0 Lock dependency to version 11.30.1 or later. 2. For npm: 'npm update auth0-lock'. 3. For yarn: 'yarn upgrade auth0-lock'. 4. Rebuild and redeploy your application.
🔧 Temporary Workarounds
Input Validation and Output Encoding
allImplement strict input validation and proper output encoding for any user input passed to flashMessage or languageDictionary features.
Disable Vulnerable Features
allTemporarily disable flashMessage and languageDictionary features if they're not essential for your implementation.
🧯 If You Can't Patch
- Implement Content Security Policy (CSP) headers to restrict script execution
- Deploy a Web Application Firewall (WAF) with XSS protection rules
🔍 How to Verify
Check if Vulnerable:
Check your package.json or lock file for auth0-lock version. If version is 11.30.0 or earlier, you are vulnerable.Check Version:
npm list auth0-lock or yarn list auth0-lockVerify Fix Applied:
Verify auth0-lock version is 11.30.1 or later in your package.json or lock file after update.📡 Detection & Monitoring
Log Indicators:
- Unusual URL parameters containing script tags or JavaScript code in authentication requests
- Multiple failed authentication attempts with suspicious parameters
Network Indicators:
- HTTP requests with script tags or JavaScript in URL parameters to authentication endpoints
- Unusual outbound connections from authentication pages
SIEM Query:
source="web_server" AND (url="*<script*" OR url="*javascript:*" OR url="*onerror=*" OR url="*onload=*") AND endpoint="*/auth/*"🔗 References
- https://github.com/auth0/lock/commit/d139cf01c8234b07caf265e051f39d3eab08f7ed
- https://github.com/auth0/lock/releases/tag/v11.30.1
- https://github.com/auth0/lock/security/advisories/GHSA-jr3j-whm4-9wwm
- https://github.com/auth0/lock/commit/d139cf01c8234b07caf265e051f39d3eab08f7ed
- https://github.com/auth0/lock/releases/tag/v11.30.1
- https://github.com/auth0/lock/security/advisories/GHSA-jr3j-whm4-9wwm
