reap / rules / recon: capability surface
Unauthenticated resources/list returns 1 item(s)
mcp-resources-prompts-exposure ASI02 Tool Misuse and Exploitation severity: low
What it detects
Unauthenticated resources/list and prompts/list. ASI02.
Calls resources/list and prompts/list with no auth; flags either returning items to an anonymous caller (finding ID suffixed per method).
applies to MCP endpoints
Why it matters
Resource and prompt listings widen what an unauthenticated caller can enumerate and later target.
Example finding
LOW mcp-resources-prompts-exposure HIGH CONFIDENCE Unauthenticated resources/list returns 1 item(s) resources/list succeeded without credentials and returned 1 item(s) to an anonymous caller. Evidence POST /mcp → 200
from a scan of reap-range, bad target
Fix
Gate resource/prompt listings behind authentication if their contents aren't meant to be public.
On reap-range
| insecure target | bad/mcp (200 unauth) · Low each |
| correct target | bad/mcp/gated and good/mcp both 401 |
Run only this check
reap -t https://your-host/mcp --authorized --include mcp-resources-prompts-exposure
Not installed? Install REAP. Only scan systems you own or are authorised to test. Reference: docs/PROBES.md.