CVE-2025-66630
📋 TL;DR
Fiber web framework versions before 2.52.11 on Go versions prior to 1.24 may generate predictable UUIDs when crypto/rand fails to obtain secure randomness. This affects security-critical pathways using Fiber's UUID functions, including session management, CSRF protection, and request-ID generation. Applications using default Fiber middleware configurations are vulnerable.
💻 Affected Systems
- Fiber web framework
📦 What is this software?
Fiber by Gofiber
⚠️ Risk & Real-World Impact
Worst Case
Attackers could predict session IDs, CSRF tokens, or rate limiting identifiers, leading to session hijacking, CSRF attacks, or bypassing security controls.
Likely Case
Predictable identifiers in security mechanisms could enable session fixation, CSRF exploitation, or request ID collisions in distributed systems.
If Mitigated
With proper monitoring and additional security layers, impact is limited to potential identifier collisions rather than direct exploitation.
🎯 Exploit Status
Exploitation requires specific conditions where crypto/rand fails to obtain secure randomness, which is environment-dependent.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 2.52.11
Vendor Advisory: https://github.com/gofiber/fiber/security/advisories/GHSA-68rr-p4fp-j59v
Restart Required: Yes
Instructions:
1. Update Fiber dependency to version 2.52.11 or later. 2. Update go.mod to require github.com/gofiber/fiber/v2 v2.52.11. 3. Run 'go mod tidy'. 4. Rebuild and redeploy application.
🔧 Temporary Workarounds
Upgrade Go Runtime
allUpgrade to Go 1.24 or later where crypto/rand has improved error handling
Download and install Go 1.24+ from https://go.dev/dl/
Update PATH and rebuild application
Custom UUID Implementation
allImplement custom UUID generation with proper error handling instead of using Fiber's utils.UUIDv4()
🧯 If You Can't Patch
- Implement additional authentication/authorization layers to reduce reliance on UUID-based security
- Monitor for unusual patterns in session usage or CSRF token validation failures
🔍 How to Verify
Check if Vulnerable:
Check go.mod for Fiber version and Go version. Vulnerable if Fiber <2.52.11 AND Go <1.24.Check Version:
grep 'github.com/gofiber/fiber/v2' go.mod && go versionVerify Fix Applied:
Confirm go.mod requires github.com/gofiber/fiber/v2 v2.52.11+ and Go version is 1.24+📡 Detection & Monitoring
Log Indicators:
- Repeated UUID patterns in session logs
- Multiple requests with identical request IDs
Network Indicators:
- Predictable session cookie values across requests
- Consistent CSRF token patterns
SIEM Query:
session_id:* AND count(session_id) > threshold OR request_id:* AND count(request_id) > threshold