CVE-2021-21698 : Security Advisory and Response

Jenkins Subversion Plugin 2.15.0 and earlier versions are impacted by a vulnerability that allows an attacker to access a subversion key file on the controller from an agent. This CVE was published on November 4, 2021, and falls under the category of Improper Limitation of a Pathname to a Restricted Directory.

Understanding CVE-2021-21698

This section will provide an in-depth understanding of the CVE-2021-21698 vulnerability.

What is CVE-2021-21698?

CVE-2021-21698 affects Jenkins Subversion Plugin versions 2.15.0 and earlier, enabling attackers to look up a subversion key file on the controller from an agent without proper restrictions.

The Impact of CVE-2021-21698

The vulnerability in Jenkins Subversion Plugin can be exploited by malicious actors to access sensitive files, potentially leading to unauthorized information disclosure or further attacks.

Technical Details of CVE-2021-21698

Let's delve into the technical aspects of CVE-2021-21698 to understand its implications better.

Vulnerability Description

Jenkins Subversion Plugin versions 2.15.0 and earlier do not restrict the file name when searching for a subversion key file, leaving an opening for threat actors to access files improperly.

Affected Systems and Versions

The issue impacts Jenkins Subversion Plugin versions up to and including 2.15.0, with no specified custom versions mentioned in the advisory.

Exploitation Mechanism

By leveraging this vulnerability, attackers can exploit the improper file name lookup to gain unauthorized access to sensitive files on the controller from an agent.

Mitigation and Prevention

To safeguard your systems from CVE-2021-21698, it is crucial to implement the following mitigation strategies.

Immediate Steps to Take

Upgrade Jenkins Subversion Plugin to a version beyond 2.15.0 that includes a patch for the vulnerability.
Monitor for any unusual file access patterns.

Long-Term Security Practices

Regularly update Jenkins and its plugins to ensure you have the latest security patches installed.
Conduct security audits to identify and address vulnerabilities proactively.

Patching and Updates

Stay informed about security advisories and promptly apply patches released by Jenkins to address known vulnerabilities.