Review follow-up on #84203. Both points reproduce; neither was a regression
from the first pass, but both are live bypasses of the same guard.
**Privilege and namespace wrappers were missing.** The allowlist covered the
coreutils-shaped wrappers but not the privilege ones, so each of these ran a
lifecycle script straight past the walk:
pkexec bash ~/restart.sh
runuser -u root -- bash ~/restart.sh
setpriv --reuid=0 -- bash ~/restart.sh
systemd-run --scope bash ~/restart.sh
nsenter --target 1 --mount bash ~/restart.sh
unshare -r bash ~/restart.sh
Added `pkexec`, `su`, `runuser`, `setpriv`, `systemd-run`, `nsenter` and
`unshare`, each with the value-taking options that would otherwise be
mistaken for the command (`nsenter -t 1`, `systemd-run -p X=1`,
`runuser -u root`, …).
**An option can carry a command STRING, not an argv tail.** `env -S` and
`su`/`runuser` `-c` take shell source. The peel treated the operand as an
opaque value and skipped it, so `env -S 'bash ~/restart.sh'` was never
scanned — the string went unread rather than being recursed into.
`_STRING_COMMAND_OPTIONS` now names those options and their values are
re-scanned as shell source, the same treatment `sh -c` payloads already get.
They are read at the ORIGINAL command token, before the transparent-prefix
peel, because peeling past `su`/`env` would discard the very option carrying
the command. `--opt value` and `--opt=value` are both handled.
Scope, stated plainly: this is an enumerated allowlist, not a general
solution to "wrapper that execs its tail". A wrapper outside the set, or a
value-taking option outside these tables, still resolves to no reference —
that fails open, exactly as it did before this PR, and it is a miss rather
than a false block. The reviewer offered "extend the set with tests, or
document that the list is heuristic"; this does the first and states the
second.
Tests: 23 new cases (220 in the file) — every added wrapper against a script
reference including the value-operand option forms, both command-string
option spellings for env/su/runuser, and the same wrappers around ordinary
work (`pkexec systemctl status nginx`, `su -c 'ls -la'`, `env -S 'echo hi'`,
`nsenter -t 1 -m ps aux`) which must stay allowed. 15 fail on the tree
before this commit.
False positives re-checked at scale: the 9,258 command lines from this
repo's own scripts and docs give an identical verdict set before and after —
0 new false positives, 0 lost detections, 0 exceptions.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_011cSddnhxiUmdGbgyKnpg8p
RickyYii
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