CVE-2021-21673 : Security Advisory and Response

Jenkins CAS Plugin version 1.6.0 and earlier incorrectly validates redirect URLs after login, making it vulnerable to phishing attacks.

Understanding CVE-2021-21673

This CVE focuses on a security issue in the Jenkins CAS Plugin versions up to 1.6.0.

What is CVE-2021-21673?

CVE-2021-21673 refers to a vulnerability in the Jenkins CAS Plugin where an attacker can trick users into visiting malicious websites by manipulating redirect URLs.

The Impact of CVE-2021-21673

The vulnerability allows attackers to conduct phishing attacks on unsuspecting users, potentially leading to sensitive information exposure or unauthorized access.

Technical Details of CVE-2021-21673

This section provides a deeper look into the specifics of the vulnerability.

Vulnerability Description

Jenkins CAS Plugin versions 1.6.0 and below fail to properly verify the legitimacy of redirect URLs after user login, enabling attackers to craft malicious URLs.

Affected Systems and Versions

The vulnerability affects Jenkins CAS Plugin versions up to 1.6.0.

Exploitation Mechanism

Attackers exploit the improper validation of redirect URLs to craft malicious links that appear legitimate, leading users to phishing websites.

Mitigation and Prevention

Protecting systems from CVE-2021-21673 requires immediate action and long-term security measures.

Immediate Steps to Take

Users are advised to update the Jenkins CAS Plugin to a secure version (above 1.6.0) and be cautious of clicking on suspicious links.

Long-Term Security Practices

Implementing secure coding practices, conducting regular security audits, and educating users on recognizing phishing attempts can improve overall security posture.

Patching and Updates

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