CVE-2024-25190
📋 TL;DR
CVE-2024-25190 is a timing side-channel vulnerability in l8w8jwt 2.2.1 that allows attackers to bypass authentication by exploiting non-constant-time memcmp comparisons. This affects any system using this JWT library for authentication. Attackers can potentially forge valid authentication tokens without proper credentials.
💻 Affected Systems
- l8w8jwt
📦 What is this software?
L8w8jwt by Glitchedpolygons
⚠️ Risk & Real-World Impact
Worst Case
Complete authentication bypass leading to unauthorized access to protected systems, data theft, privilege escalation, and full system compromise.
Likely Case
Authentication bypass in applications using l8w8jwt for JWT validation, allowing unauthorized access to protected resources and APIs.
If Mitigated
Limited impact with proper network segmentation, additional authentication layers, and monitoring for anomalous authentication attempts.
🎯 Exploit Status
Timing attacks require statistical analysis and multiple attempts, but tools exist to automate this. Exploitation is practical for determined attackers.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 2.2.2 or later
Vendor Advisory: https://github.com/GlitchedPolygons/l8w8jwt
Restart Required: No
Instructions:
1. Update l8w8jwt to version 2.2.2 or later using package manager. 2. Rebuild and redeploy applications using the library. 3. Test authentication functionality.
🔧 Temporary Workarounds
Replace memcmp with constant-time comparison
allImplement custom constant-time comparison function for JWT signature verification
// Example C code: implement constant_time_memcmp() using bitwise operations
Add rate limiting
allImplement strict rate limiting on authentication endpoints to reduce timing attack feasibility
// Configure web server or application rate limiting rules
🧯 If You Can't Patch
- Implement additional authentication factors (MFA) to reduce impact of JWT bypass
- Deploy WAF with JWT validation rules and timing attack detection
🔍 How to Verify
Check if Vulnerable:
Check package.json or build configuration for l8w8jwt version 2.2.1Check Version:
npm list l8w8jwt # for Node.js applicationsVerify Fix Applied:
Verify l8w8jwt version is 2.2.2 or later in dependencies📡 Detection & Monitoring
Log Indicators:
- Multiple failed authentication attempts with similar tokens
- Successful authentication from unusual IPs/times
- JWT validation errors
Network Indicators:
- High volume of authentication requests to same endpoint
- Pattern of requests with incremental token changes
SIEM Query:
source="auth.log" AND ("authentication failed" OR "invalid token") | stats count by src_ip | where count > 100