CVE-2025-68158
📋 TL;DR
This CSRF vulnerability in Authlib allows attackers to bypass Cross-Site Request Forgery protections in OAuth flows. Attackers can hijack authentication sessions by obtaining valid state tokens through their own authentication attempts. This affects all users of Authlib 1.6.5 and earlier who use cache-backed state storage.
💻 Affected Systems
- Authlib
📦 What is this software?
Authlib by Authlib
⚠️ Risk & Real-World Impact
Worst Case
Attackers could hijack user authentication sessions, potentially gaining unauthorized access to user accounts and sensitive data through OAuth/OpenID Connect integrations.
Likely Case
Attackers could perform CSRF attacks against OAuth flows, potentially compromising user sessions in applications using vulnerable Authlib configurations.
If Mitigated
With proper session validation and CSRF protections in the application layer, impact would be limited to failed authentication attempts.
🎯 Exploit Status
Attack requires attacker to initiate their own authentication flow to obtain valid state tokens, which is straightforward.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 1.6.6
Vendor Advisory: https://github.com/authlib/authlib/security/advisories/GHSA-fg6f-75jq-6523
Restart Required: Yes
Instructions:
1. Update Authlib to version 1.6.6 or later using pip: pip install --upgrade authlib>=1.6.6
2. Restart all services using Authlib
3. Verify the update was successful
🔧 Temporary Workarounds
Disable cache-backed state storage
allSwitch to memory-backed state storage instead of cache-backed storage
Modify Authlib configuration to use memory storage instead of cache storage
🧯 If You Can't Patch
- Implement additional CSRF protections at the application layer
- Monitor authentication logs for suspicious OAuth state token usage patterns
🔍 How to Verify
Check if Vulnerable:
Check Authlib version: python -c "import authlib; print(authlib.__version__)"Check Version:
python -c "import authlib; print(authlib.__version__)"Verify Fix Applied:
Verify version is 1.6.6 or higher and check that state tokens are now properly tied to user sessions📡 Detection & Monitoring
Log Indicators:
- Multiple authentication attempts with same state token from different sessions
- OAuth state validation failures
Network Indicators:
- Unusual OAuth callback patterns
- CSRF attempts against authentication endpoints
SIEM Query:
authlib OR oauth AND (state_token OR csrf) AND (failure OR multiple_sessions)🔗 References
- https://github.com/authlib/authlib/commit/2808378611dd6fb2532b189a9087877d8f0c0489
- https://github.com/authlib/authlib/commit/7974f45e4d7492ab5f527577677f2770ce423228
- https://github.com/authlib/authlib/security/advisories/GHSA-fg6f-75jq-6523
- https://github.com/authlib/authlib/security/advisories/GHSA-fg6f-75jq-6523
