CVE-2021-21606 Explained : Impact and Mitigation

Jenkins 2.274 and earlier, LTS 2.263.1 and earlier improperly validate the format of a provided fingerprint ID, allowing an attacker to check for the existence of XML files with a short path. This vulnerability has been assigned the CVE ID of CVE-2021-21606.

Understanding CVE-2021-21606

This section delves deeper into the impact and technical details of CVE-2021-21606.

What is CVE-2021-21606?

CVE-2021-21606 is a vulnerability in Jenkins 2.274 and earlier, LTS 2.263.1 and earlier that results from improper validation of a provided fingerprint ID, enabling an attacker to check for the existence of XML files with a short path.

The Impact of CVE-2021-21606

The vulnerability allows malicious actors to exploit the Jenkins platform to verify the existence of XML files using crafted fingerprint IDs, potentially leading to unauthorized data retrieval or further attacks.

Technical Details of CVE-2021-21606

Let's explore the technical specifics of CVE-2021-21606 in this section.

Vulnerability Description

The flaw in Jenkins versions 2.274 and below, and LTS versions 2.263.1 and below, permits attackers to verify the presence of specific XML files through manipulation of fingerprint IDs without proper validation.

Affected Systems and Versions

Products impacted include Jenkins with versions less than 2.274 and LTS less than 2.263.1, provided by the Jenkins project.

Exploitation Mechanism

By utilizing improperly validated fingerprint IDs, threat actors can exploit this vulnerability to search for XML files with shortened paths on affected Jenkins instances.

Mitigation and Prevention

Discover the necessary steps to address and defend against CVE-2021-21606 below.

Immediate Steps to Take

Organizations should apply security patches promptly, monitor system logs for suspicious activities, and restrict access to Jenkins instances to prevent exploitation.

Long-Term Security Practices

Implementing robust input validation mechanisms, regular security audits, and employee training on identifying and reporting security issues can enhance the overall security posture.

Patching and Updates

Stay informed about security advisories from the Jenkins project and promptly apply recommended patches and updates to mitigate the risk of CVE-2021-21606.