CVE-2025-3757
📋 TL;DR
OpenPubkey library versions before 0.10.0 contain a signature verification bypass vulnerability in JWS (JSON Web Signature) handling. Attackers can forge signatures to impersonate legitimate users or services. Any application using vulnerable OpenPubkey versions for authentication or authorization is affected.
💻 Affected Systems
- OpenPubkey library
📦 What is this software?
Openpubkey by Openpubkey
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise through forged authentication tokens, allowing attackers to impersonate any user, escalate privileges, or bypass all access controls.
Likely Case
Authentication bypass leading to unauthorized access to protected resources, data theft, or privilege escalation.
If Mitigated
Limited impact if additional authentication layers exist, but signature-based trust is still broken.
🎯 Exploit Status
CWE-305 indicates authentication bypass, suggesting straightforward exploitation once the JWS manipulation method is known.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 0.10.0
Vendor Advisory: https://github.com/openpubkey/openpubkey
Restart Required: No
Instructions:
1. Update OpenPubkey dependency to version 0.10.0 or later. 2. For Go projects: run 'go get github.com/openpubkey/openpubkey@v0.10.0'. 3. Rebuild and redeploy applications.
🔧 Temporary Workarounds
Input validation for JWS tokens
allImplement additional validation of JWS token structure before passing to OpenPubkey
🧯 If You Can't Patch
- Implement additional authentication layers (MFA, IP whitelisting)
- Monitor for anomalous authentication patterns and JWS token usage
🔍 How to Verify
Check if Vulnerable:
Check package.json, go.mod, or dependency files for OpenPubkey version <0.10.0Check Version:
For Go: 'go list -m github.com/openpubkey/openpubkey'Verify Fix Applied:
Confirm OpenPubkey version is 0.10.0 or higher in dependency files📡 Detection & Monitoring
Log Indicators:
- Failed signature verification attempts
- Unusual authentication patterns
- JWS tokens with unexpected structure
Network Indicators:
- Authentication requests with malformed JWS tokens
- Traffic spikes to authentication endpoints
SIEM Query:
Authentication logs where JWS verification status changes unexpectedly