CVE-2021-37860 : What You Need to Know

A user-assisted attacker can inject arbitrary web script in Mattermost 5.38 and earlier versions due to insufficient clipboard content sanitization.

Understanding CVE-2021-37860

This vulnerability in Mattermost allows for cross-site scripting (XSS) attacks due to a lack of proper input validation.

What is CVE-2021-37860?

The vulnerability in Mattermost 5.38 and earlier versions enables attackers to insert malicious web scripts in deployments that disable the default Content Security Policy.

The Impact of CVE-2021-37860

The impact is rated as LOW severity, with a CVSS base score of 3.7. Attackers can execute XSS attacks with low privileges required.

Technical Details of CVE-2021-37860

This section provides specific technical details on the vulnerability.

Vulnerability Description

Mattermost versions 5.38 and below do not adequately sanitize clipboard contents, allowing for the injection of arbitrary web scripts.

Affected Systems and Versions

The vulnerability affects Mattermost versions up to and including 5.38, impacting deployments that explicitly disable the default Content Security Policy.

Exploitation Mechanism

The vulnerability can be exploited by a user-assisted attacker to execute cross-site scripting attacks in affected Mattermost deployments.

Mitigation and Prevention

Learn how to address and prevent this vulnerability in your system.

Immediate Steps to Take

Users are advised to update to a patched version or apply recommended security updates to mitigate the risk.

Long-Term Security Practices

Implement robust input validation and security controls to prevent XSS attacks and secure your Mattermost deployment.

Patching and Updates

Regularly check for security updates from Mattermost and apply patches promptly to bolster system security.