CVE-2021-21695 : What You Need to Know

A detailed overview of CVE-2021-21695, a vulnerability affecting Jenkins versions 2.318 and earlier, LTS 2.303.2 and earlier.

Understanding CVE-2021-21695

This section covers the essential information regarding the CVE-2021-21695 vulnerability.

What is CVE-2021-21695?

The vulnerability in Jenkins allows FilePath#listFiles to list files outside authorized directories when following symbolic links in affected versions.

The Impact of CVE-2021-21695

CVE-2021-21695 poses a risk as it enables unauthorized access to files by bypassing directory restrictions in Jenkins instances.

Technical Details of CVE-2021-21695

Explore the technical aspects of CVE-2021-21695 to understand its implications and severity.

Vulnerability Description

FilePath#listFiles can potentially access files outside permitted directories due to symbolic link handling in Jenkins versions specified.

Affected Systems and Versions

The vulnerability affects Jenkins versions 2.318 and below, as well as LTS 2.303.2 and earlier versions.

Exploitation Mechanism

By leveraging FilePath#listFiles, threat actors can navigate to restricted directories and retrieve sensitive files by exploiting symbolic link traversal.

Mitigation and Prevention

Discover the steps to mitigate the risks associated with CVE-2021-21695 and prevent potential exploits.

Immediate Steps to Take

Implement access controls, restrict symbolic link following, and update Jenkins to a patched version to mitigate the vulnerability.

Long-Term Security Practices

Establish stringent file access policies, conduct regular security audits, and train personnel on secure coding practices to enhance overall Jenkins security.

Patching and Updates

Stay informed about security advisories, apply security patches promptly, and monitor Jenkins security channels for updates on vulnerabilities.