CVE-2021-21605 : What You Need to Know

Jenkins 2.274 and earlier, LTS 2.263.1 and earlier allow users with Agent/Configure permission to choose agent names that can override the global

config.xml

file. This vulnerability is assigned as CVE-2021-21605.

Understanding CVE-2021-21605

This section provides insights into the impact and technical details of the CVE-2021-21605 vulnerability.

What is CVE-2021-21605?

CVE-2021-21605 is a security vulnerability in Jenkins versions 2.274 and earlier, LTS 2.263.1 and earlier, that enables users with specific permissions to manipulate agent names and override crucial configuration files.

The Impact of CVE-2021-21605

The vulnerability allows users to exploit the Agent/Configure permission to choose agent names that can alter the global

config.xml

file, compromising the integrity and security of the Jenkins environment.

Technical Details of CVE-2021-21605

In this section, we delve into the technical aspects of CVE-2021-21605, including the description, affected systems and versions, and exploitation mechanism.

Vulnerability Description

CVE-2021-21605 arises from improper validation of user inputs, enabling unauthorized users to manipulate agent names and impact the

config.xml

file.

Affected Systems and Versions

Jenkins versions up to 2.274 and LTS versions up to 2.263.1 are impacted by CVE-2021-21605, specifically affecting users with Agent/Configure permissions.

Exploitation Mechanism

Exploiting CVE-2021-21605 involves users with Agent/Configure permission selecting agent names that trigger overrides of the global

config.xml

, leading to unauthorized changes.

Mitigation and Prevention

To secure your system against CVE-2021-21605, immediate actions, long-term security practices, and the importance of patching and updates are crucial.

Immediate Steps to Take

Ensure restricting permissions, monitoring agent name changes, and reviewing

config.xml

alterations to mitigate immediate risks posed by CVE-2021-21605.

Long-Term Security Practices

Implement a least-privilege model, conduct regular security audits, and educate users on secure configurations to prevent similar vulnerabilities.

Patching and Updates

Regularly update Jenkins to versions beyond 2.274 and LTS versions higher than 2.263.1, where fixes for CVE-2021-21605 have been implemented.