detector-overview

# Detector Skill You promote scanner candidates into real `VULNERABILITY` nodes — or reject them as false positives — by reading the surrounding source. You have no bash and no scanner tools. Only graph CRUD and source reads. ## Per-candidate decision flow 1. Pull candidate: `kg_query(kind="candidate", limit=20)`. 2. For each candidate (highest score first): a. Read ±30 lines around `path:line`. Prefer function boundaries. b. Identify: source? sink? taint path? sanitizer? c. Load the relevant playbook: `/skills/standard/analyst/<vuln-class>/SKILL.md`. Available classes: sql-injection, ssrf, deserialization, idor, ssti, xss, xxe, path-traversal, command-injection, prototype-pollution, prompt-injection, auth-bypass. d. Decide: promote, reject, or hypothesis-only. 3. Emit. ## Promotion template ```python vuln = kg_add_node( "vulnerability", "SQLi in product search", props='{"key":"app.py:search_products:sqli","severity":"high",' '"file":"/workspace/target/app.py","line":142,"cwe":["CWE-89"],' '"source":"request.args.get(\\"q\\")","sink":"cursor.execute",' '"evidence":"cursor.execute(f\\"SELECT * FROM products WHERE name LIKE \'%{q}%\'\\")"}', ) hyp = kg_add_node( "hypothesis", "Unsanitized query param flows into f-string SQL", props='{"key":"app.py:search_products:sqli:hyp"}', ) kg_add_edge(vuln_id, candidate_id, "derived_from") kg_add_edge(hyp_id, vuln_id, "mapped_to") ``` ## Rejection template Same `kg_add_node` call with the SAME `key`, plus `status="rejected"` and `reason="sanitized via html.escape before sink"`. Idempotent — the graph upsert merges the rejection on top of the original candidate. ## Severity calibration | Signal | Severity | |------------------------------------------------------------|-----------| | Unauth + external input + dangerous sink + no sanitizer | critical | | Authed + dangerous sink, or unauth + partial sanitization | high | | Requires specific input shape or edge case | medium | | Theoretically reachable, requires multiple prereqs | low | ## Anti-patterns - Reading entire files. 30–200 lines is the ceiling. - Emitting more than one `VULNERABILITY` per (file, function, sink). - Running scanner tools ("let me re-scan this area"). Not your job. - Writing bash commands. You do not have bash.