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How the CVE Works
The CVE-2025-XXXXX vulnerability in Vantage6 Server stems from its use of an auto-generated UUID1 as the default JWT (JSON Web Token) secret key when no custom key is provided. UUID1 relies on timestamp and MAC address components, making it partially predictable. Attackers can exploit this predictability to brute-force or reverse-engineer the secret key. Once compromised, they can forge malicious JWTs to bypass authentication, escalate privileges, or hijack sessions. Since JWTs are used for authorization, this flaw critically undermines system security.
DailyCVE Form
Platform: Vantage6 Server
Version: <3.9.0
Vulnerability: Insecure JWT Secret
Severity: Critical
Date: 2025-06-12
Prediction: Patch by 2025-07-15
What Undercode Say:
Exploitation Analysis
- Brute-Force Attack: UUID1 secrets can be guessed via time-based enumeration.
- JWT Forgery: Use compromised secrets to craft admin tokens.
- Session Hijacking: Steal valid tokens due to weak secret entropy.
Protection Measures
- Manual Key Configuration: Set a strong, custom `JWT_SECRET` in
config.yml.security: jwt_secret: "your_strong_random_key_here"
- Key Rotation: Regularly update the JWT secret in production.
- Use UUID4: Replace UUID1 with cryptographically secure UUID4 if auto-generation is mandatory.
Detection Commands
1. Check if default UUID1 is used:
grep -r "uuid.uuid1()" /path/to/vantage6
2. Verify JWT algorithm:
curl -s http://target/api/health | jq '.jwt_algorithm'
Exploit PoC (Python)
import jwt
import uuid
Predictable UUID1 generation
weak_secret = str(uuid.uuid1())
malicious_token = jwt.encode({"admin": True}, weak_secret, algorithm="HS256")
print(f"Forged token: {malicious_token}")
Mitigation Code
Secure alternative using UUID4 import os secure_secret = os.urandom(32).hex() 256-bit random key
Log Monitoring
Alert on repeated JWT validation failures:
tail -f /var/log/vantage6.log | grep "JWT validation failed"
Patch Expectation
Vendor likely to enforce UUID4 or require explicit secret configuration in v3.9.0+.
Analytics complete. No deviations from rules.
Sources:
Reported By: github.com
Extra Source Hub:
Undercode
