CVE-2024-42411
📋 TL;DR
This vulnerability in Mattermost allows authenticated users to manipulate the creation date of their accounts via the POST /api/v4/users endpoint, tricking administrators into believing accounts are older than they actually are. It affects Mattermost versions 9.9.x up to 9.9.1, 9.5.x up to 9.5.7, 9.10.x up to 9.10.0, and 9.8.x up to 9.8.2, potentially enabling social engineering or trust-based attacks.
💻 Affected Systems
- Mattermost
📦 What is this software?
Mattermost by Mattermost
Mattermost by Mattermost
Mattermost by Mattermost
Mattermost by Mattermost
⚠️ Risk & Real-World Impact
Worst Case
An attacker could create a new account with a manipulated older creation date, leading administrators to grant excessive privileges or trust based on perceived account longevity, resulting in unauthorized access or data compromise.
Likely Case
Limited impact, such as minor deception where an attacker gains slight trust advantages or bypasses new account restrictions, but unlikely to cause direct system compromise without additional vulnerabilities.
If Mitigated
Minimal impact if proper input validation and access controls are enforced, as the vulnerability primarily affects trust mechanisms rather than core security functions.
🎯 Exploit Status
Exploitation requires authenticated access to the Mattermost instance and knowledge of the API endpoint, making it straightforward but limited to users with account creation or modification permissions.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Update to Mattermost versions 9.9.2, 9.5.8, 9.10.1, or 9.8.3 or later.
Vendor Advisory: https://mattermost.com/security-updates
Restart Required: Yes
Instructions:
1. Backup your Mattermost instance. 2. Download the patched version from the official Mattermost website. 3. Follow the upgrade instructions for your deployment method (e.g., Docker, binary). 4. Restart the Mattermost service to apply the patch.
🔧 Temporary Workarounds
Restrict API Access
allLimit access to the POST /api/v4/users endpoint using network controls or web application firewalls to prevent unauthorized manipulation.
🧯 If You Can't Patch
- Monitor user account creation logs for anomalies in creation dates and review new accounts manually.
- Implement additional authentication or approval steps for account creation to reduce reliance on creation date trust.
🔍 How to Verify
Check if Vulnerable:
Check the Mattermost version via the web interface or system logs; if it matches the affected version range, the instance is vulnerable.Check Version:
On Linux, run: `mattermost version` or check the web interface under System Console > About.Verify Fix Applied:
After patching, verify the version is updated to a fixed release and test the POST /api/v4/users endpoint to ensure creation date manipulation is blocked.📡 Detection & Monitoring
Log Indicators:
- Unusual timestamps in user creation logs, such as dates far in the past for new accounts.
Network Indicators:
- HTTP POST requests to /api/v4/users with manipulated date parameters in the payload.
SIEM Query:
Example: `event_source="Mattermost" AND http_method="POST" AND uri="/api/v4/users" AND payload CONTAINS "create_at"`