CVE-2018-1000409 : Exploit Details and Defense Strategies

Jenkins versions 2.145 and prior, as well as LTS versions 2.138.1 and prior, have a session fixation vulnerability that affects the proper session handling when a user registers for a new account.

Understanding CVE-2018-1000409

This CVE involves a session fixation vulnerability in Jenkins versions 2.145 and earlier, as well as LTS 2.138.1 and earlier.

What is CVE-2018-1000409?

This vulnerability is located in the file HudsonPrivateSecurityRealm.java within the core/src/main/java/hudson/security/ directory. It impacts Jenkins' ability to invalidate the current session and generate a fresh one when a user signs up for a new account.

The Impact of CVE-2018-1000409

The vulnerability affects the security of Jenkins instances by allowing the persistence of session data, potentially leading to unauthorized access and security breaches.

Technical Details of CVE-2018-1000409

This section provides more in-depth technical insights into the CVE.

Vulnerability Description

The vulnerability exists in the core/src/main/java/hudson/security/HudsonPrivateSecurityRealm.java file, preventing Jenkins from properly handling session invalidation and creation for new user registrations.

Affected Systems and Versions

Jenkins versions 2.145 and earlier
LTS versions 2.138.1 and earlier

Exploitation Mechanism

Attackers can exploit this vulnerability by fixing a session to gain unauthorized access to Jenkins instances, potentially compromising sensitive data and system integrity.

Mitigation and Prevention

Protecting systems from CVE-2018-1000409 requires immediate actions and long-term security practices.

Immediate Steps to Take

Update Jenkins to the latest patched version that addresses the session fixation vulnerability.
Monitor user sessions for any suspicious activities that could indicate unauthorized access.

Long-Term Security Practices

Implement multi-factor authentication to enhance user account security.
Regularly audit and review session management practices to identify and mitigate potential vulnerabilities.

Patching and Updates

Apply security patches provided by Jenkins to fix the session fixation vulnerability and enhance overall system security.