CVE-2021-37865 : What You Need to Know

A detailed analysis of the CVE-2021-37865 vulnerability affecting Mattermost.

Understanding CVE-2021-37865

This section provides insights into the nature and impact of CVE-2021-37865.

What is CVE-2021-37865?

The CVE-2021-37865 vulnerability impacts Mattermost version 6.2 and earlier, allowing authenticated users to trigger resource exhaustion by uploading a malicious GIF file during post drafting, leading to a server-side Denial of Service.

The Impact of CVE-2021-37865

The vulnerability poses a medium risk, with a CVSS base score of 4.3. Exploitation of the flaw could result in server downtime due to resource exhaustion, affecting the availability of the service.

Technical Details of CVE-2021-37865

This section delves into the specifics of the vulnerability.

Vulnerability Description

Mattermost fails to adequately process a maliciously crafted GIF file during post creation, enabling authenticated users to exhaust resources, thereby causing denial of service.

Affected Systems and Versions

Mattermost versions 6.2 and below are impacted by this vulnerability, while versions 6.1.1, 6.0.4, 5.39.3, and 5.37.6 are unaffected.

Exploitation Mechanism

Authenticated users can exploit this vulnerability by uploading a specially crafted GIF file during post drafting, triggering resource exhaustion on the server.

Mitigation and Prevention

Here we discuss steps to mitigate and prevent exploitation of CVE-2021-37865.

Immediate Steps to Take

Users are advised to update Mattermost to versions beyond 6.2 to prevent exploitation. Additionally, restricting file uploads can help mitigate the risk.

Long-Term Security Practices

Regularly updating the Mattermost software, implementing security patches, and educating users on safe file upload practices can enhance security posture.

Patching and Updates

Staying informed about security updates from Mattermost and promptly applying patches can help address known vulnerabilities and enhance system security.