CVE-2025-56404
📋 TL;DR
CVE-2025-56404 is an information disclosure vulnerability in MariaDB MCP 0.1.0 where the SSE (Server-Sent Events) service lacks user validation, allowing attackers to access sensitive information. This affects organizations using MariaDB MCP 0.1.0 with the SSE service enabled. Attackers can potentially retrieve confidential data without authentication.
💻 Affected Systems
- MariaDB MCP
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Attackers gain unauthorized access to sensitive database information, configuration details, or credentials stored in the MCP service, leading to data breaches and compliance violations.
Likely Case
Unauthenticated attackers extract configuration information, metadata, or limited sensitive data from the SSE service endpoints.
If Mitigated
With proper network segmentation and access controls, impact is limited to isolated systems with minimal sensitive data exposure.
🎯 Exploit Status
Exploitation appears straightforward - attackers can directly query SSE endpoints without authentication. No public exploit code identified yet.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Not available
Vendor Advisory: https://github.com/MariaDB/mcp/issues/17
Restart Required: Yes
Instructions:
1. Monitor MariaDB MCP repository for security updates. 2. Apply patch when available. 3. Restart MCP service after patching. 4. Verify SSE service no longer allows unauthenticated access.
🔧 Temporary Workarounds
Disable SSE Service
allDisable the Server-Sent Events service if not required for functionality
Edit MCP configuration to disable SSE endpoints
Set sse_enabled = false in config file
Network Access Control
linuxRestrict network access to MCP SSE service ports
iptables -A INPUT -p tcp --dport [MCP_PORT] -s [TRUSTED_NETWORK] -j ACCEPT
iptables -A INPUT -p tcp --dport [MCP_PORT] -j DROP
🧯 If You Can't Patch
- Implement strict network segmentation to isolate MCP service from untrusted networks
- Deploy web application firewall (WAF) rules to block unauthorized SSE endpoint access
🔍 How to Verify
Check if Vulnerable:
Check if MariaDB MCP version is 0.1.0 and SSE endpoints are accessible without authentication. Test with: curl -v http://[MCP_HOST]:[PORT]/sse-endpointsCheck Version:
Check MCP version in configuration files or via service status outputVerify Fix Applied:
After applying workarounds, verify SSE endpoints require authentication or return access denied. Test with: curl -v http://[MCP_HOST]:[PORT]/sse-endpoints and confirm 401/403 response.📡 Detection & Monitoring
Log Indicators:
- Unauthenticated access to /sse or similar SSE endpoints
- Multiple failed authentication attempts followed by successful SSE access
- Unusual outbound data transfers from MCP service
Network Indicators:
- Unusual traffic patterns to MCP SSE ports from unauthorized sources
- Large data transfers from MCP service to external IPs
SIEM Query:
source="mcp.log" AND (uri_path="/sse*" OR uri_path="/*sse*") AND http_status=200 AND auth_status="none"