CVE-2025-26340: Q-free Maxtime Auth Bypass Vulnerability

CVE-2025-26340 Overview

CVE-2025-26340 is a critical cryptographic vulnerability affecting Q-Free MaxTime, a traffic management and parking solution. The vulnerability stems from the use of a hard-coded cryptographic key (CWE-321) in the JWT (JSON Web Token) signing mechanism. This weakness allows an unauthenticated remote attacker to bypass the authentication system entirely via crafted HTTP requests, potentially gaining unauthorized access to the application.

Critical Impact

Unauthenticated attackers can bypass authentication and gain full access to Q-Free MaxTime systems by exploiting the hard-coded JWT signing key to forge valid authentication tokens.

Affected Products

• Q-Free MaxTime version 2.11.0 and earlier
• All Q-Free MaxTime deployments using JWT-based authentication with default configurations

Discovery Timeline

• 2025-02-12 - CVE CVE-2025-26340 published to NVD
• 2025-10-24 - Last updated in NVD database

Technical Details for CVE-2025-26340

Vulnerability Analysis

This vulnerability represents a fundamental cryptographic implementation flaw in Q-Free MaxTime's authentication mechanism. The application uses JWT tokens for authenticating users and managing sessions. However, instead of using a securely generated, unique cryptographic key for signing these tokens, the application employs a hard-coded key that is embedded directly in the software.

JWTs consist of three parts: a header, a payload, and a signature. The signature is generated using a secret key to ensure the token's integrity and authenticity. When this key is hard-coded and discoverable, an attacker can extract it through reverse engineering or code analysis. Once obtained, the attacker can forge arbitrary JWT tokens with any desired claims, including administrative privileges.

The network-accessible nature of this vulnerability means that any attacker who can reach the Q-Free MaxTime web interface can potentially exploit this flaw without any prior authentication or user interaction beyond initial access.

Root Cause

The root cause of CVE-2025-26340 is the insecure practice of embedding a static cryptographic key directly within the application code or configuration files. This violates fundamental cryptographic security principles which require that signing keys be:

1. Uniquely generated for each deployment
2. Stored securely outside of application code
3. Rotated periodically
4. Protected from unauthorized access

By hard-coding the JWT signing key, the developers created a scenario where every installation of Q-Free MaxTime versions 2.11.0 and below shares the same signing secret, making the vulnerability universally exploitable across all affected deployments.

Attack Vector

The attack exploits the network-accessible authentication endpoint of Q-Free MaxTime. An attacker can execute the following attack sequence:

1. Key Discovery: Extract the hard-coded JWT signing key from the application through binary analysis, configuration file access, or other reconnaissance methods
2. Token Forgery: Create a valid JWT token with elevated privileges using the discovered key
3. Authentication Bypass: Submit crafted HTTP requests with the forged JWT token to authenticate as any user, including administrators
4. System Compromise: Gain full access to the Q-Free MaxTime system, allowing manipulation of traffic management data and system configurations

The vulnerability allows unauthenticated remote access, which could lead to complete system compromise including unauthorized access to sensitive data, integrity violations through data manipulation, and availability impacts through administrative actions.

Detection Methods for CVE-2025-26340

Indicators of Compromise

• Unexpected administrative login sessions from unknown IP addresses or geographic locations
• JWT tokens in access logs containing unusual payload claims or timestamps
• Authentication attempts with tokens signed using the known hard-coded key pattern
• Anomalous HTTP request patterns targeting authentication endpoints
• User accounts showing activity at times when legitimate users were not active

Detection Strategies

• Implement deep packet inspection to analyze JWT tokens in HTTP traffic for signatures matching the compromised key
• Deploy application-level monitoring to detect authentication bypass attempts and unusual token validation patterns
• Configure SIEM rules to alert on successful authentications from previously unseen sources or during unusual hours
• Monitor for binary analysis tools or debugging activity that could indicate key extraction attempts

Monitoring Recommendations

• Enable detailed logging for all authentication events including token validation success and failure
• Implement real-time alerting for administrative access from untrusted networks
• Monitor network traffic to Q-Free MaxTime instances for patterns consistent with token forgery attacks
• Establish baseline authentication patterns and alert on significant deviations

How to Mitigate CVE-2025-26340

Immediate Actions Required

• Upgrade Q-Free MaxTime to a version newer than 2.11.0 that addresses the hard-coded key vulnerability
• Review all Q-Free MaxTime access logs for signs of unauthorized access or suspicious authentication patterns
• Implement network segmentation to restrict access to Q-Free MaxTime systems from untrusted networks
• Enable additional authentication factors where supported to reduce the impact of JWT-based authentication bypass
• Contact Q-Free support for vendor-specific guidance on secure key generation and configuration

Patch Information

Organizations should consult the Nozomi Networks Vulnerability Advisory for detailed remediation guidance. Upgrading to a patched version that implements unique, securely-generated JWT signing keys is the definitive fix for this vulnerability. Ensure that after patching, new cryptographic keys are generated and all existing JWT tokens are invalidated.

Workarounds

• Place Q-Free MaxTime behind a VPN or reverse proxy requiring pre-authentication to limit exposure
• Implement IP-based access restrictions to allow connections only from trusted management networks
• Deploy a Web Application Firewall (WAF) configured to inspect and validate JWT tokens before they reach the application
• Enable session timeout policies to reduce the window of opportunity for exploiting forged tokens
• Implement additional network monitoring at perimeter devices to detect and block suspicious authentication traffic

# Network access restriction example (firewall rules)
# Restrict Q-Free MaxTime access to trusted management subnet only
# Example using iptables - adapt to your firewall platform

# Allow access from trusted management network
iptables -A INPUT -p tcp --dport 443 -s 10.0.100.0/24 -j ACCEPT

# Drop all other connections to the application port
iptables -A INPUT -p tcp --dport 443 -j DROP

# Log dropped connection attempts for monitoring
iptables -A INPUT -p tcp --dport 443 -j LOG --log-prefix "MaxTime-Blocked: "