CVE-2025-20381
📋 TL;DR
This vulnerability allows authenticated users of Splunk MCP Server app to bypass SPL command restrictions by embedding commands as sub-searches. Attackers could execute unauthorized SPL commands beyond the intended allowlist controls. Only affects users with access to the 'run_splunk_query' MCP tool in vulnerable versions.
💻 Affected Systems
- Splunk MCP Server app
⚠️ 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
Privileged user could execute arbitrary SPL commands to access sensitive data, modify configurations, or disrupt Splunk operations.
Likely Case
Authorized users exceeding their intended permissions to access data or perform actions outside their role scope.
If Mitigated
Limited impact if proper network segmentation and least privilege access controls are already implemented.
🎯 Exploit Status
Exploitation requires authenticated access to the vulnerable MCP tool.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 0.2.4
Vendor Advisory: https://advisory.splunk.com/advisories/SVD-2025-1210
Restart Required: Yes
Instructions:
1. Access Splunk Web interface. 2. Navigate to Apps > Manage Apps. 3. Locate 'MCP Server' app. 4. Click 'Upgrade' or install version 0.2.4. 5. Restart Splunk instance.
🔧 Temporary Workarounds
Restrict MCP tool access
allTemporarily remove or restrict access to 'run_splunk_query' MCP tool for non-essential users.
Implement additional SPL validation
allAdd custom validation layer to check for sub-search patterns in SPL queries.
🧯 If You Can't Patch
- Implement strict role-based access control for MCP tools
- Monitor and audit all SPL queries executed through MCP tools
🔍 How to Verify
Check if Vulnerable:
Check MCP Server app version in Splunk Web: Apps > Manage Apps > MCP ServerCheck Version:
| rest /services/apps/local | search label="MCP Server" | table versionVerify Fix Applied:
Confirm MCP Server app version is 0.2.4 or higher📡 Detection & Monitoring
Log Indicators:
- Unusual SPL query patterns with nested sub-searches from MCP tools
- SPL commands outside expected allowlist
Network Indicators:
- Increased MCP tool usage patterns
- Unusual query volumes from specific users
SIEM Query:
index=_audit action="search" search="*subsearch*" app="mcp_server" | stats count by user, search