CVE-2024-51750
📋 TL;DR
A malicious Matrix homeserver can send specially crafted invalid messages over federation that cause Element Web and Desktop clients to fail rendering messages or entire rooms. This affects all users of vulnerable Element Web and Desktop versions connecting to malicious homeservers.
💻 Affected Systems
- Element Web
- Element Desktop
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Complete denial of service where users cannot access messages or entire rooms in Element clients, potentially disrupting communication.
Likely Case
Temporary rendering failures for specific messages or rooms until the client is refreshed or the malicious content is removed.
If Mitigated
Minimal impact with proper patching; clients gracefully handle invalid messages without rendering failures.
🎯 Exploit Status
Exploitation requires control of a homeserver to send malicious messages over federation to target clients.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 1.11.85
Vendor Advisory: https://github.com/element-hq/element-web/security/advisories/GHSA-w36j-v56h-q9pc
Restart Required: Yes
Instructions:
1. Update Element Web to version 1.11.85 or later via your package manager or download from official sources. 2. Update Element Desktop to version 1.11.85 or later via auto-update or manual download. 3. Restart the client after updating.
🔧 Temporary Workarounds
Disable federation
allPrevent connection to external homeservers to block malicious messages from reaching clients.
🧯 If You Can't Patch
- Restrict client connections to trusted homeservers only.
- Monitor for rendering failures and refresh clients if issues occur.
🔍 How to Verify
Check if Vulnerable:
Check Element client version in settings; if below 1.11.85, it is vulnerable.Check Version:
In Element client: Settings → Help & About → VersionVerify Fix Applied:
Confirm version is 1.11.85 or higher in client settings after update.📡 Detection & Monitoring
Log Indicators:
- Client logs showing rendering errors or crashes when processing messages.
- Homeserver logs with unusual federation message patterns.
Network Indicators:
- Unusual federation traffic from untrusted homeservers.
SIEM Query:
Search for error logs containing 'rendering failed' or 'message processing error' in Element client logs.