CVE-2019-20857 : Vulnerability Insights and Analysis

A vulnerability has been found in Mattermost Server prior to version 5.16.0, allowing attackers to trigger a denial of service attack by using an excessive number of backtick characters.

Understanding CVE-2019-20857

This CVE identifies a vulnerability in Mattermost Server that can lead to a denial of service attack.

What is CVE-2019-20857?

This vulnerability in Mattermost Server before version 5.16.0 enables attackers to cause a denial of service by exploiting the markdown renderer with an abundance of backtick characters.

The Impact of CVE-2019-20857

The vulnerability can result in a hang in the markdown renderer, leading to a denial of service attack.

Technical Details of CVE-2019-20857

This section provides technical details of the CVE.

Vulnerability Description

An issue in Mattermost Server before version 5.16.0 allows attackers to trigger a denial of service by overloading the markdown renderer with excessive backtick characters.

Affected Systems and Versions

Affected System: Mattermost Server
Affected Versions: Prior to 5.16.0

Exploitation Mechanism

Attackers can exploit this vulnerability by utilizing a large number of backtick characters to overload the markdown renderer, causing a denial of service.

Mitigation and Prevention

Protect your systems from CVE-2019-20857 with the following steps:

Immediate Steps to Take

Upgrade Mattermost Server to version 5.16.0 or newer to mitigate the vulnerability.
Monitor system logs for any unusual activity that could indicate an attack.

Long-Term Security Practices

Regularly update software and apply security patches to prevent vulnerabilities.
Implement network and application firewalls to filter and monitor traffic.

Patching and Updates

Stay informed about security updates and patches released by Mattermost.
Apply patches promptly to ensure your systems are protected against known vulnerabilities.