Advisor review on the prior commit (69cad7c) caught a real detection-kill
vulnerability before push: reading `commons.root` from the SCANNED
TARGET's .llm-security/policy.json let a hostile cloned repo redirect
llm-security's own detection corpus to an attacker-supplied (empty)
one, with graceful-empty fallback making the substitution silent — a
substitutive override, unlike sig.custom_rules_path's additive one.
Dropped the policy import entirely; commons location is this plugin's
own concern, resolved only from __dirname or an explicit test/dev
override, never from policy or the scan target.
Also fixed two issues the review surfaced:
- Default vendor path was repo-root `shared/`, which package.json's
`files` allowlist (bin/, scanners/, knowledge/) would never publish —
moved under scanners/commons/, inside the directory that actually
ships. Same defect class as 2fe2915 (green dev checkout, empty
detection tables once installed).
- Cache keyed success/failure together, so the first caller's
`fallback` shape (e.g. []) leaked to a second caller expecting a
different shape ({}) on the same missing artifact. Cache now stores
a load-failed sentinel and returns each caller's own fallback.
Loaded artifacts are also deep-frozen, since the cache hands out one
shared object by reference to every caller.
New/changed tests cover all four: a simulated hostile-target policy
file is ignored, the failure-cache no longer cross-contaminates
fallback shapes, and mutating a loaded artifact throws.
Golden baseline unchanged; full suite 2063/2063.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QAYkRaBXT6tmWXTQAi1ZBg
Thin, sync-read JSON artifact loader for the future vendored
llm-security-commons subtree, modeled on signature-scanner.mjs's
loadRules()/loadCustomRules() pair: process-cached, graceful-empty
fallback on any read/parse error, and policy-extensible via a
`commons.root` policy value (mirrors sig.custom_rules_path).
Unit-tested now against a local fixture — Phase 4 (commons repo
creation, gated on the operator creating the Forgejo remote) hasn't
run yet, so the default `shared/` vendor path doesn't exist in this
checkout. That "not vendored yet" case is itself asserted: the loader
must degrade to the caller's fallback, not crash.
Not wired to any consumer yet (that's Phase 5 step 4, table-by-table
behind the golden gate). No CLI/hook/scanner-visible behaviour exists
to document. Golden baseline unchanged; full suite 2063/2063 (2053 +
10 new).
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QAYkRaBXT6tmWXTQAi1ZBg
