CVE-2025-59786: 2N Access Commander Auth Bypass Flaw

CVE-2025-59786 Overview

2N Access Commander version 3.4.2 and prior contains an improper session invalidation vulnerability (CWE-613) that allows multiple session cookies to remain active after a user logs out of the web application. This session management flaw means that previously issued authentication tokens are not properly revoked upon logout, potentially allowing unauthorized access if an attacker can obtain a valid session token through network interception, browser history, or other means.

Critical Impact

Session tokens remain valid after logout, enabling potential unauthorized access to the 2N Access Commander web interface through session hijacking or replay attacks.

Affected Products

• 2N Access Commander version 3.4.2 and prior versions
• All deployments using the affected web application authentication mechanism

Discovery Timeline

• March 4, 2026 - CVE-2025-59786 published to NVD
• March 5, 2026 - Last updated in NVD database

Technical Details for CVE-2025-59786

Vulnerability Analysis

This vulnerability stems from insufficient session lifecycle management within the 2N Access Commander web application. When a user initiates a logout action, the application fails to properly invalidate all associated session tokens on the server side. As a result, session cookies that were previously issued remain valid and can be used to authenticate subsequent requests even after the user believes they have securely ended their session.

The attack requires network-level access to intercept session tokens and depends on user interaction with the logout functionality, making exploitation more complex. However, successful exploitation could result in high confidentiality impact through unauthorized access to the access control management system.

Root Cause

The root cause is improper implementation of session invalidation logic (CWE-613: Insufficient Session Expiration). The web application does not maintain proper session state management on the server side, failing to revoke or expire session tokens when the logout action is triggered. This architectural weakness in the authentication subsystem allows stale sessions to persist beyond their intended lifecycle.

Attack Vector

The attack vector is network-based and requires the attacker to obtain a valid session token through methods such as:

1. Network traffic interception (man-in-the-middle attacks)
2. Cross-site scripting attacks that exfiltrate cookies
3. Access to browser storage or history on a shared workstation
4. Session token prediction or brute-forcing if tokens are weakly generated

Once a valid session token is obtained, the attacker can replay it against the 2N Access Commander web interface to gain authenticated access, even if the legitimate user has logged out. The vulnerability requires some preconditions to exploit, including obtaining the session token and timing the attack before natural token expiration (if any exists).

Detection Methods for CVE-2025-59786

Indicators of Compromise

• Multiple concurrent active sessions for a single user account from different IP addresses
• Session activity continuing after a recorded logout event in application logs
• Unusual access patterns or API calls using session tokens associated with terminated sessions
• Authentication logs showing session reuse from geographically disparate locations

Detection Strategies

• Implement logging and alerting for session reuse after logout events
• Monitor for multiple simultaneous sessions from the same user account
• Deploy network intrusion detection to identify session token replay attempts
• Correlate logout events with subsequent session activity to identify anomalies

Monitoring Recommendations

• Enable detailed authentication and session logging in 2N Access Commander
• Configure SIEM rules to alert on session activity post-logout
• Monitor for unusual access patterns to the access control management interface
• Implement user session auditing to track all active sessions per account

How to Mitigate CVE-2025-59786

Immediate Actions Required

• Upgrade 2N Access Commander to version 3.5 or later as indicated in the vendor advisory
• Force all users to re-authenticate after applying the patch
• Review access logs for any suspicious session activity
• Implement additional network controls to protect session token transmission

Patch Information

2N has released a security update addressing this vulnerability. Detailed patch information and upgrade instructions are available in the 2N CVE-2025-59786 Security Advisory. Organizations should upgrade to Access Commander version 3.5 or later to remediate this vulnerability.

Workarounds

• Enforce HTTPS-only access to prevent session token interception
• Implement shorter session timeout values to reduce the window of opportunity
• Deploy Web Application Firewall (WAF) rules to detect and block session replay attempts
• Educate users to clear browser data after sessions on shared workstations
• Consider implementing additional authentication factors for sensitive operations