CVE-2021-21621 Explained : Impact and Mitigation

Jenkins Support Core Plugin versions up to 2.72 are affected by a vulnerability that exposes serialized user authentication, including session IDs in the support bundle creation process.

Understanding CVE-2021-21621

This CVE affects Jenkins Support Core Plugin versions up to 2.72.

What is CVE-2021-21621?

Jenkins Support Core Plugin versions up to 2.72 expose serialized user authentication data, including session IDs, during support bundle creation.

The Impact of CVE-2021-21621

This vulnerability could lead to the exposure of sensitive user data, increasing the risk of unauthorized access and information leakage.

Technical Details of CVE-2021-21621

The following are the technical details related to this CVE:

Vulnerability Description

Affected versions of Jenkins Support Core Plugin allow the disclosure of serialized user authentication information during support bundle creation.

Affected Systems and Versions

Affected Versions: Up to 2.72
Unaffected Versions: 2.70.1, 2.68.1

Exploitation Mechanism

In certain configurations, the session ID of the user creating the support bundle can be included in the serialized user authentication data.

Mitigation and Prevention

To address CVE-2021-21621, consider the following steps:

Immediate Steps to Take

Upgrade to a non-vulnerable version, starting from 2.70.1.
Avoid sharing support bundles in configurations where sensitive auth data exposure is a concern.

Long-Term Security Practices

Regularly monitor Jenkins security advisories and update to the latest secure versions.
Implement proper access controls to limit exposure of sensitive information.

Patching and Updates

Stay informed about security patches released by Jenkins project and promptly apply them to eliminate vulnerabilities.