CVE-2019-20858 : Security Advisory and Response

A vulnerability in Mattermost Server prior to version 5.15.0 allows attackers to launch a denial of service attack by manipulating characters in a SQL LIKE clause targeting an APIv4 endpoint.

Understanding CVE-2019-20858

This CVE identifies a flaw in Mattermost Server that can lead to a denial of service attack through excessive CPU consumption.

What is CVE-2019-20858?

This vulnerability in Mattermost Server allows malicious actors to induce a denial of service attack by inserting manipulated characters into a SQL LIKE clause targeting an APIv4 endpoint.

The Impact of CVE-2019-20858

Attackers can cause a denial of service by triggering excessive CPU usage.

Technical Details of CVE-2019-20858

This section provides technical details about the vulnerability.

Vulnerability Description

An issue in Mattermost Server before version 5.15.0 enables attackers to cause a denial of service attack by manipulating characters in a SQL LIKE clause targeting an APIv4 endpoint.

Affected Systems and Versions

Affected Version: Mattermost Server prior to 5.15.0

Exploitation Mechanism

Attackers can induce a denial of service attack by inserting manipulated characters into a SQL LIKE clause targeting an APIv4 endpoint.

Mitigation and Prevention

Protect your systems from CVE-2019-20858 with the following steps:

Immediate Steps to Take

Upgrade Mattermost Server to version 5.15.0 or later to mitigate the vulnerability.
Monitor CPU usage for any unusual spikes that could indicate a denial of service attack.

Long-Term Security Practices

Regularly update and patch software to prevent known vulnerabilities.
Implement input validation to prevent SQL injection attacks.

Patching and Updates

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