CVE-2017-18903 : Security Advisory and Response

A vulnerability was found in Mattermost Server versions older than 4.0.0, 3.10.2, and 3.9.2, potentially leading to CSRF (Cross-Site Request Forgery) if CORS (Cross-Origin Resource Sharing) is enabled.

Understanding CVE-2017-18903

This CVE identifies a security issue in Mattermost Server versions.

What is CVE-2017-18903?

CVE-2017-18903 is a vulnerability in Mattermost Server versions prior to 4.0.0, 3.10.2, and 3.9.2 that could result in CSRF attacks when CORS is active.

The Impact of CVE-2017-18903

The vulnerability could allow malicious actors to perform Cross-Site Request Forgery attacks if CORS is enabled on affected versions of Mattermost Server.

Technical Details of CVE-2017-18903

This section provides technical insights into the CVE.

Vulnerability Description

The issue in Mattermost Server versions before 4.0.0, 3.10.2, and 3.9.2 allows for CSRF attacks in the presence of enabled CORS.

Affected Systems and Versions

Mattermost Server versions older than 4.0.0
Mattermost Server versions 3.10.2 and 3.9.2

Exploitation Mechanism

The vulnerability can be exploited by attackers to forge requests and perform unauthorized actions if CORS is configured.

Mitigation and Prevention

Protect your systems from CVE-2017-18903 with the following measures.

Immediate Steps to Take

Update Mattermost Server to versions 4.0.0 or newer to mitigate the CSRF vulnerability.
Disable CORS if not required for your application to reduce the attack surface.

Long-Term Security Practices

Regularly monitor security advisories and updates from Mattermost to stay informed about potential vulnerabilities.
Implement secure coding practices to prevent CSRF and other web-based attacks.

Patching and Updates

Apply patches and updates provided by Mattermost promptly to address security vulnerabilities and enhance system security.