Commit graph

2 commits

Author SHA1 Message Date
Daniel Han
07c7f9bfca
Package scanners: close fail-open gaps in the sdist fallback and hidden-payload paths (#6359)
* Package scanners: close fail-open gaps in the sdist fallback and hidden-payload paths

Follow-up hardening on the now-blocking scanners so the enforcing gate cannot
report clean while a malicious artifact goes unscanned.

scan_packages.py
- Hidden payload: also flag a network call AND an os/subprocess exec that live
  only in a blanked docstring/string of an exec/eval file (the fetch-then-run
  shape of an exec(__doc__) dropper). Either alone in real code was already
  covered; hidden together they are the payload.
- Pinned releases fail closed: _release_files no longer falls back to the latest
  artifact when a pinned version is missing or empty, so a yanked/bad pin is an
  error instead of a different file being scanned in its place.
- requires_dist is read from the pinned release's metadata, not the project-level
  (latest) document, so a sdist-only pin follows its own dependency tree.
- Environment markers are evaluated (PEP 508) instead of dropping any marker that
  merely contains the word extra, so default-true markers like extra != 'dev' are
  kept; conservative fallback keeps a dep on any uncertainty.
- Transitive recovery is a depth-bounded worklist: a wheel dependency whose own
  child is sdist-only is fetched (--no-deps) and scanned, then its children are
  recovered in turn, rather than being silently skipped.

scan_npm_packages.py
- Baseline keys use the package-relative path instead of the basename, so the
  same basename in a different directory is not over-suppressed.

Tests cover each case; full scripts pass AST and ruff checks.

* Address review: tighten marker scope, decoy-proof the dropper check, fail closed on missing pin metadata

- Markers: keep any dep whose marker can hold on another install target
  (sys_platform == 'win32', python_version == '3.13'); only drop a marker that
  depends solely on extra and is false with no extra. A scanner runs on one
  target but must cover code installed on others. Pure-extra markers are
  evaluated against default_environment() with extra unset.
- Hidden dropper: the network+exec docstring check now inspects the removed
  (blanked) span directly, so a benign visible network or subprocess call cannot
  mask a payload that still lives in a docstring. Carrier checks stay
  blanked-only (an in-code carrier is already caught by the normal check), so
  corpus findings are unchanged.
- requires_dist: a pinned version whose own metadata cannot be fetched recovers
  nothing rather than substituting the latest release's dependency tree.
- Transitive recovery: the last-ditch direct-sdist branch also chases the
  recovered package's declared deps, matching the other branches.
- npm baseline: schema bumped to v2 (package-relative keys); a pre-v2 baseline
  with entries is ignored (fail closed) instead of mis-applying basename keys.

Tests cover each case; scripts pass AST, ruff, and the import-hoist verifier.

* Scanner: exclude comments from hidden-payload check, flag missing pin metadata as incomplete

Hidden network+exec detection now inspects only docstring/string spans (what exec(__doc__)/exec(<str>) can actually run), so a real exec() beside comments that mention a network and a subprocess call no longer false-positives. Missing pinned-release metadata in transitive recovery records a download_error so the --with-deps path fails closed instead of treating it as no dependencies. Adds regression tests for both.

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
2026-06-18 06:50:16 -07:00
Daniel Han
21612c2e32
Package scanners: cut false positives and make the CI gate blocking (#6355)
* Package scanners: cut false positives and make the CI gate blocking

scan_packages.py and scan_npm_packages.py red-failed on legitimate
library code, so the security-audit steps were left advisory. Reduce
the false positives at the source and flip both gates to blocking.

scan_packages.py:
- Scan code only: blank comments and bare docstrings/doctests before
  matching (line numbers preserved), so prose and >>> examples cannot
  trip a finding.
- Drop the platform.system() branch from the anti-analysis regex (under
  DOTALL it matched across the whole file, so every cross-platform
  library tripped it) and fix the dead /proc/self/status alternative.
- Add a reviewed baseline allowlist (scan_packages_baseline.json) keyed
  on (package, basename, check): only non-baselined CRITICAL/HIGH exit
  1, and a new kind of finding in a listed file still fails.
- sdist fallback: when --with-deps cannot resolve a shard (a sdist-only
  package or a version conflict), drop to per-spec and fetch the raw
  sdist from the PyPI JSON API (no pip build, no setup.py), so every
  package is still scanned and no shard exits 2.

scan_npm_packages.py:
- Mirror the code-only JS/TS scanning (blank // and /* */ comments,
  string/template/regex aware) and the baseline allowlist. The npm
  corpus is clean today, so the baseline is empty.

security-audit.yml:
- Flip both scan steps to blocking (SCAN_ENFORCE=1), capturing the
  scanner exit via PIPESTATUS so tee does not mask it.

tests/security: add coverage for the strip, baseline and sdist paths.

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* Address review feedback on the package scanners

- Do not blank f-strings during code-only scanning (they evaluate at
  import); and when a file uses exec/eval, rescan the original for
  payload carriers hidden in a docstring/string so exec(__doc__) style
  payloads stay visible.
- sdist fallback: recover transitive deps with their version specifier
  (fetch the pinned version, not latest), and recover deps in the
  --no-deps branch too so a sdist-only transitive dependency is still
  scanned instead of silently skipped.
- Baseline: key by package-relative path, not basename, so a future
  same-named file in another directory is not auto-suppressed.
  Regenerated the baseline accordingly.

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
2026-06-16 01:46:15 -07:00