CVE-2025-6514
📋 TL;DR
CVE-2025-6514 is a critical OS command injection vulnerability in mcp-remote that allows remote code execution when connecting to malicious MCP servers. Attackers can craft authorization_endpoint URLs to execute arbitrary commands on the client system. Anyone using mcp-remote to connect to untrusted MCP servers is affected.
💻 Affected Systems
- mcp-remote
⚠️ 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
Full system compromise with attacker gaining complete control over the client system, enabling data theft, lateral movement, and persistent access.
Likely Case
Remote code execution leading to data exfiltration, cryptocurrency mining, or deployment of ransomware on vulnerable systems.
If Mitigated
Limited impact if systems only connect to trusted MCP servers with proper input validation and network segmentation.
🎯 Exploit Status
Exploitation requires tricking users into connecting to malicious MCP servers or compromising trusted servers.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Commit 607b226a356cb61a239ffaba2fb3db1c9dea4bac
Vendor Advisory: https://github.com/geelen/mcp-remote/commit/607b226a356cb61a239ffaba2fb3db1c9dea4bac
Restart Required: No
Instructions:
1. Update mcp-remote to latest version. 2. Verify installation includes commit 607b226a. 3. Test connectivity with trusted MCP servers.
🔧 Temporary Workarounds
Restrict MCP Server Connections
allOnly allow connections to trusted, verified MCP servers using allowlists.
Network Segmentation
allIsolate mcp-remote instances in restricted network segments.
🧯 If You Can't Patch
- Disable mcp-remote functionality entirely until patching is possible
- Implement strict network controls to prevent connections to untrusted servers
🔍 How to Verify
Check if Vulnerable:
Check if mcp-remote version predates commit 607b226a356cb61a239ffaba2fb3db1c9dea4bacCheck Version:
git log --oneline -1Verify Fix Applied:
Verify current installation includes commit 607b226a or later📡 Detection & Monitoring
Log Indicators:
- Unusual command execution patterns
- Connections to unknown MCP servers
- Suspicious authorization_endpoint URLs
Network Indicators:
- Outbound connections to suspicious MCP servers
- Unexpected command and control traffic
SIEM Query:
process: 'mcp-remote' AND (url: '*;*' OR url: '*|*' OR url: '*`*')