CVE-2021-21663 : Security Advisory and Response

A missing permission check in Jenkins XebiaLabs XL Deploy Plugin 7.5.8 and earlier versions allows attackers with Overall/Read permission to connect to a specified URL using specific credentials IDs, potentially exposing sensitive information stored in Jenkins.

Understanding CVE-2021-21663

This CVE pertains to a vulnerability in the Jenkins XebiaLabs XL Deploy Plugin that can be exploited by users with specific permissions to access unauthorized URLs.

What is CVE-2021-21663?

The vulnerability in Jenkins XebiaLabs XL Deploy Plugin versions prior to 7.5.8 enables attackers with Overall/Read permission to establish connections to custom URLs using credentials obtained through other means, potentially leading to a security breach.

The Impact of CVE-2021-21663

The CVE poses a significant risk as attackers can utilize the vulnerability to capture sensitive Username/password credentials stored in Jenkins, compromising the security and integrity of the system.

Technical Details of CVE-2021-21663

The technical details of CVE-2021-21663 include:

Vulnerability Description

The vulnerability arises from a missing permission check in Jenkins XebiaLabs XL Deploy Plugin, enabling unauthorized users to connect to attacker-specified URLs using credentials IDs, which can result in unauthorized access to sensitive data.

Affected Systems and Versions

The affected product is the Jenkins XebiaLabs XL Deploy Plugin, particularly versions less than 7.5.6 and less than or equal to 7.5.8, provided by the Jenkins project.

Exploitation Mechanism

Exploiting this vulnerability requires perpetrators to have Overall/Read permissions, allowing them to connect to malicious URLs using specific credentials obtained through alternative methods.

Mitigation and Prevention

To safeguard your systems from potential exploitation of CVE-2021-21663, consider the following mitigation strategies:

Immediate Steps to Take

Upgrade the Jenkins XebiaLabs XL Deploy Plugin to version 7.5.8 or above to mitigate the vulnerability.
Restrict Overall/Read permissions to authorized personnel only to prevent unauthorized access.

Long-Term Security Practices

Regularly review and update access control policies within Jenkins to ensure least privilege access.
Conduct security training for personnel to enhance awareness of potential risks.

Patching and Updates

Stay informed about security advisories from Jenkins project and promptly apply patches or updates to address any known vulnerabilities.