CVE-2021-39878 : Security Advisory and Response

The stored Reflected Cross-Site Scripting vulnerability in the Jira integration in GitLab versions 13.0 up to 14.3.1 allowed attackers to execute arbitrary JavaScript code.

Understanding CVE-2021-39878

This CVE discloses details about a Cross-Site Scripting vulnerability in GitLab affecting versions 13.0 to 14.3.1.

What is CVE-2021-39878?

The vulnerability allowed malicious actors to execute arbitrary JavaScript code through the Jira integration in GitLab versions 13.0 to 14.3.1.

The Impact of CVE-2021-39878

The impact is assessed with a CVSSv3.1 base score of 5.8 (Medium), with high confidentiality impact and user interaction required for exploitation.

Technical Details of CVE-2021-39878

This section outlines the technical details of the vulnerability.

Vulnerability Description

A stored Reflected Cross-Site Scripting vulnerability in the Jira integration in GitLab versions 13.0 up to 14.3.1 allowed an attacker to execute arbitrary JavaScript code.

Affected Systems and Versions

Product: GitLab
Vendor: GitLab
Affected Versions: >=13.0, <14.1.7, >=14.2, <14.2.5, >=14.3, <14.3.1

Exploitation Mechanism

Attack Complexity: HIGH
Attack Vector: NETWORK
Privileges Required: LOW
User Interaction: REQUIRED

Mitigation and Prevention

To mitigate the risks associated with CVE-2021-39878, follow these steps:

Immediate Steps to Take

Implement the available patch provided by GitLab.
Monitor for any suspicious activities on the GitLab Jira integration.
Educate users on the risks of executing untrusted code.

Long-Term Security Practices

Regularly update GitLab to the latest version.
Conduct security trainings for developers on secure coding practices.

Patching and Updates

Ensure timely updates from GitLab to address security vulnerabilities.