CVE-2024-46872
📋 TL;DR
Mattermost fails to sanitize user inputs in the frontend that are used for redirection, allowing a one-click client-side path traversal that leads to Cross-Site Request Forgery (CSRF) in Playbooks. This vulnerability affects Mattermost versions 9.10.x up to 9.10.2, 9.11.x up to 9.11.1, and 9.5.x up to 9.5.9. Attackers can trick authenticated users into performing unintended actions in Playbooks via malicious links.
💻 Affected Systems
- Mattermost
📦 What is this software?
Mattermost Server by Mattermost
Mattermost Server by Mattermost
Mattermost Server by Mattermost
⚠️ Risk & Real-World Impact
Worst Case
An attacker could perform unauthorized actions in Playbooks on behalf of authenticated users, potentially modifying workflows, deleting data, or escalating privileges within the Mattermost instance.
Likely Case
Attackers trick users into clicking malicious links that perform unwanted actions in Playbooks, such as modifying tasks or changing settings without user consent.
If Mitigated
With proper CSRF protections and input validation, the attack would fail, preventing unauthorized actions even if users click malicious links.
🎯 Exploit Status
Exploitation requires user interaction (one-click) and authenticated user session. Attack vector is through malicious links targeting Playbooks.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 9.10.3, 9.11.2, 9.5.10
Vendor Advisory: https://mattermost.com/security-updates
Restart Required: Yes
Instructions:
1. Backup your Mattermost instance. 2. Download and install the patched version (9.10.3, 9.11.2, or 9.5.10). 3. Restart the Mattermost service. 4. Verify the update was successful.
🔧 Temporary Workarounds
Disable Playbooks
allTemporarily disable Playbooks functionality to prevent exploitation
Edit config.json: set "EnablePlaybooks" to false
Restart Mattermost service
Implement WAF Rules
allAdd web application firewall rules to block suspicious redirection patterns
Add WAF rule to detect and block path traversal attempts in redirect parameters
🧯 If You Can't Patch
- Implement strict Content Security Policy (CSP) headers to restrict redirections
- Educate users about not clicking untrusted links in Mattermost
🔍 How to Verify
Check if Vulnerable:
Check Mattermost version via System Console > About or run: mattermost versionCheck Version:
mattermost versionVerify Fix Applied:
Verify version is 9.10.3, 9.11.2, or 9.5.10 or higher📡 Detection & Monitoring
Log Indicators:
- Unusual redirect patterns in access logs
- Multiple failed Playbooks actions from same user session
Network Indicators:
- Suspicious outbound redirects from Mattermost instance
- Unexpected Playbooks API calls
SIEM Query:
source="mattermost" AND (url="*redirect*" OR action="playbook*") AND status=200