Learn about CVE-2021-21639 affecting Jenkins versions 2.286 and earlier, LTS 2.277.1 and earlier. Understand the impact, technical details, and mitigation steps to address this vulnerability.
Jenkins 2.286 and earlier, LTS 2.277.1 and earlier are affected by a vulnerability that allows attackers with specific permissions to replace a node with a different type by manipulating the
config.xml
REST API endpoint.
Understanding CVE-2021-21639
This CVE details a security flaw in Jenkins versions 2.286 and prior, as well as LTS versions 2.277.1 and earlier.
What is CVE-2021-21639?
CVE-2021-21639 is a vulnerability in Jenkins that arises from a lack of validation for the type of object created after submitting data to the
config.xml
REST API endpoint of a node.
The Impact of CVE-2021-21639
The vulnerability enables attackers with specific permissions to replace a node with a different type within the Jenkins application.
Technical Details of CVE-2021-21639
This section provides further technical insights into the vulnerability.
Vulnerability Description
The issue in Jenkins allows attackers with Computer/Configure permissions to perform unauthorized replacement of nodes within the application.
Affected Systems and Versions
Jenkins versions 2.286 and prior, as well as LTS versions 2.277.1 and earlier, are impacted by this security flaw.
Exploitation Mechanism
Attackers can exploit this vulnerability by manipulating the data submitted to the
config.xml
REST API endpoint of a node.
Mitigation and Prevention
Protecting your system from CVE-2021-21639 requires immediate action.
Immediate Steps to Take
Ensure that Jenkins is updated to a patched version that addresses this vulnerability. Additionally, review and restrict permissions for sensitive operations within Jenkins.
Long-Term Security Practices
Implement a regular security patch management process to stay protected against emerging threats like CVE-2021-21639.
Patching and Updates
Regularly monitor and apply security updates released by Jenkins to mitigate the risk of such vulnerabilities in the future.