GHSA-3xm7-qw7j-qc8v SSRF in @aborruso/ckan-mcp-server via base_url allows access to internal networks

• npm @aborruso/ckan-mcp-server: < 0.4.85 → fixed in 0.4.85

Summary The `@aborruso/ckan-mcp-server` MCP server provides tools including `ckan_package_search` and `sparql_query` that accept a `base_url` parameter, making HTTP requests to arbitrary endpoints without restriction. A CKAN portal client has no legitimate reason to contact cloud metadata or internal network services. Severity Attack complexity is HIGH because exploitation requires prompt injection via malicious content (webpage, document) while the victim's AI assistant has this MCP server connected. Proof of Concept Tested inside Docker-in-Docker isolated environment with canary HTTP sidecar. ```json {"tool": "ckan_package_search", "arguments": {"base_url": "http://canary:8080/ssrf", "query": "test"}} ``` Result: Canary received 9 HTTP requests. The high request volume confirms no rate limiting or URL validation. Root Cause No URL validation on `base_url` parameter. No private IP blocking (RFC 1918, link-local 169.254.x.x), no cloud metadata blocking. The `sparql_query` and `ckan_datastore_search_sql` tools also accept arbitrary base URLs and expose injection surfaces. Impact Internal network scanning, cloud metadata theft (IAM credentials via IMDS at 169.254.169.254), potential SQL/SPARQL injection via unsanitized query parameters. Attack requires prompt injection to control the `base_url` parameter. Recommended Fix 1. Validate `base_url` against a configurable allowlist of permitted CKAN portals 2. Block private IP ranges (RFC 1918, link-local) 3. Block cloud metadata endpoints (169.254.169.254) 4. Sanitize SQL input for datastore queries 5. SPARQL endpoint allowlist Credit Discovered by Andrei Boldyrev of Munio Security Research using munio