CVE-2021-3311 Explained : Impact and Mitigation

An issue was discovered in October through build 471 that reactivates an old session ID after a new login occurs, potentially compromising security if the old session ID is known to an attacker.

Understanding CVE-2021-3311

This CVE relates to a vulnerability in October CMS that allows the reactivation of an old session ID upon a new login, contrary to the intended authentication behavior.

What is CVE-2021-3311?

CVE-2021-3311 involves the reactivation of an invalidated session ID after a new login, posing a security risk if the old session ID is in the possession of an attacker.

The Impact of CVE-2021-3311

The vulnerability could lead to unauthorized access to user accounts and sensitive information if exploited by malicious actors. It undermines the security measures established by the Auth/Manager.php authentication system.

Technical Details of CVE-2021-3311

The technical details of CVE-2021-3311 include:

Vulnerability Description

The vulnerability allows an attacker with knowledge of an old session ID to gain unauthorized access to a user account through session reactivation.

Affected Systems and Versions

October CMS through build 471 is affected by this vulnerability, potentially impacting users of the platform.

Exploitation Mechanism

By leveraging the reactivation of old session IDs post a new login, threat actors could bypass authentication controls and gain unauthorized entry.

Mitigation and Prevention

To address CVE-2021-3311, consider the following:

Immediate Steps to Take

Users should log out after each session to invalidate old session IDs.
Monitor login activities for any suspicious behavior or unauthorized access.

Long-Term Security Practices

Implement regular security updates and patches to ensure the latest security measures are in place.
Educate users about secure login practices and the importance of protecting session IDs.

Patching and Updates

Stay informed about security advisories and updates from October CMS to patch vulnerabilities and enhance overall system security.