v8.1.0 AV surface, session S1. The three poisoned fixture trees
(signature-scan/poisoned, memory-scan/poisoned-project, trigger-scan/poisoned)
are deleted from disk and materialized into a temp dir by the new
tests/helpers/payload-trees.mjs. SIG-matching strings are assembled from
fragments, the zero-width carrier comes from String.fromCodePoint, and every
file carries the sha256 of the retired on-disk bytes;
tests/helpers/payload-trees.test.mjs asserts the materialized trees are
byte-identical (mutation-checked: one changed byte fails it).
Inline payload literals in signature-scanner, signature-scanner-custom-rules
and e2e/scan-pipeline are fragmented the same way; the literal U+200B in
attack-simulator, auto-cleaner-rce and auto-cleaner-traversal is replaced by
String.fromCodePoint(0x200B).
av-surface: a 3->0, a2 3->0, c 5->1, d 5->2, b 9->8 (webshell-b64 blob gone).
What remains (c=1, d=2, b) is under examples/** or is (b), both S2.
Suite 2261 / 2252 pass / 3 fail (av-surface b, c, d only) / 6 skip.
Golden output identical before/after (109/7/4, 61/61).
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
validateContent() syntax-checked .mjs/.js/.cjs candidates via
execSync(`node --check "${tmpPath}"`), where tmpPath derives from the
untrusted scanned-repo FILENAME. The F-2 guard checks path containment
but never quotes or strips shell metacharacters, so a file named
`x";<cmd>;".mjs` in a scanned repo turned `/security clean` (live is the
documented default) into arbitrary command execution. Verified with a
live PoC before the fix.
- validateContent: spawnSync('node', ['--check', tmpPath]) — no shell.
- CLI orchestrator fallback: same treatment (argv array, explicit
status/error handling instead of execSync's throw-on-nonzero).
- Belt (defense-in-depth): applyFixes now refuses findings whose `file`
carries shell or control metacharacters, reported as skipped.
- Regression tests cover both layers separately, so the belt cannot mask
a re-introduced shell in the sink.
node --test: 1865/1865 green (1863 + 2 new).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01TcQyMTQfyrsAapaCMPxTtQ
