CVE-2020-13262 : Vulnerability Insights and Analysis

GitLab CE/EE versions 12.9 through 13.0.1 are vulnerable to client-side code injection through Mermaid markup, enabling unauthorized PUT requests.

Understanding CVE-2020-13262

This CVE involves a security vulnerability in GitLab versions 12.9 to 13.0.1 that allows malicious actors to execute client-side code injection through specially crafted Mermaid payloads.

What is CVE-2020-13262?

Client-Side code injection through Mermaid markup in GitLab CE/EE 12.9 and later through 13.0.1 allows a specially crafted Mermaid payload to PUT requests on behalf of other users via clicking on a link.

The Impact of CVE-2020-13262

CVSS Base Score: 6.1 (Medium Severity)
Attack Vector: Network
Attack Complexity: Low
User Interaction: Required
Scope: Changed
Confidentiality Impact: Low
Integrity Impact: Low
Privileges Required: None
Availability Impact: None

Technical Details of CVE-2020-13262

This section provides detailed technical information about the vulnerability.

Vulnerability Description

The vulnerability involves improper neutralization of input during web page generation ('cross-site scripting') in GitLab, allowing for code injection through Mermaid markup.

Affected Systems and Versions

Affected Product: GitLab
Affected Versions:
GitLab >=12.9, <12.9.8
GitLab >=12.10, <12.10.7
GitLab >=13.0, <13.0.1

Exploitation Mechanism

The vulnerability can be exploited by crafting a malicious Mermaid payload and tricking users into clicking on a link, which then executes unauthorized PUT requests on behalf of the user.

Mitigation and Prevention

Protect your systems from CVE-2020-13262 with the following steps:

Immediate Steps to Take

Update GitLab to a patched version that addresses the vulnerability.
Educate users about the risks of clicking on unknown links.

Long-Term Security Practices

Regularly monitor and audit your GitLab instance for any suspicious activities.
Implement security training for developers to prevent similar vulnerabilities in the future.

Patching and Updates

Stay informed about security updates from GitLab and apply patches promptly to secure your systems.