CVE-2022-4045: Denial-of-Service Vulnerability in Mattermost - Exploit Details and Mitigation Strategies

A critical denial-of-service (DoS) vulnerability has been identified in Mattermost, a popular open-source messaging and collaboration platform used by enterprises. This vulnerability has been assigned the CVE identifier CVE-2022-4045. The flaw allows an authenticated user to crash the Mattermost server by sending multiple requests to a specific API endpoint which fetches a large amount of data.

Details of the vulnerability

Mattermost provides a rich set of API endpoints that facilitate various features for its users. However, with great power comes great responsibility, and one such API endpoint has been flagged as vulnerable to DoS attacks.

By bombarding this endpoint with multiple requests, an authenticated user could potentially cause the Mattermost server to crash. This attack vector fetches substantial amounts of data, ultimately causing the server to become unresponsive and go down.

Here's an example of a sample code snippet that demonstrates the vulnerability

import requests

# Replace "your-mattermost-url" with the actual Mattermost server URL
url = "https://your-mattermost-url/api/v4/channels/{CHANNELID}/posts";

headers = {
    "Authorization": "Bearer {YOUR_ACCESS_TOKEN}"
}

payload = {
    "page": ,
    "per_page": 100000  # A large value like this could trigger the DoS
}

while True:
    response = requests.get(url, headers=headers, params=payload)
    if response.status_code != 200:
        break

Replace {CHANNELID} with a valid channel ID and {YOUR_ACCESS_TOKEN} with your own Mattermost personal access token.

Exploit details

This vulnerability can be exploited by any authenticated user who has access to the specified API endpoint, and as a result, can gain unauthorized permissions causing disruptions to the server's operations. It's crucial to address this issue quickly to avoid potential downtime for Mattermost servers.

Original references and links

1. The official Mattermost API documentation: https://api.mattermost.com/
2. Mitre CVE database entry: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-4045
3. NIST National Vulnerability Database: https://nvd.nist.gov/vuln/detail/CVE-2022-4045

Mitigation strategies

To safeguard your Mattermost server against this vulnerability, consider implementing the following mitigation strategies:

1. Update Mattermost to the latest version: Keep your Mattermost server up-to-date with the latest security patches and updates to protect against known vulnerabilities.
2. Limit API request rate: Implement rate limiting for API requests, which will reduce the flood of requests and give the server time to process and respond to each request incrementally.
3. Monitor server performance: Keep track of server performance and usage to identify any suspicious behavior or server slowdowns that could indicate an ongoing DoS attack.

Conclusion

The CVE-2022-4045 vulnerability in Mattermost could cause significant disruptions to daily business operations if left unaddressed. By understanding the exploit details and implementing appropriate mitigation strategies, you can protect your Mattermost server and keep it running smoothly.

Timeline

Published on: 11/23/2022 07:15:00 UTC
Last modified on: 11/26/2022 03:38:00 UTC