GHSA-4c7q-4928-8445 is a high-severity (CVSS 7.3) Path Traversal vulnerability in uu_chmod. O3 Security confirms whether GHSA-4c7q-4928-8445 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
chmod: --preserve-root bypassed by any path that resolves to root (e.g. /../)
Real-World Exposure
uu_chmodReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects crates.io packages — download data is not available via public APIs for these ecosystems.
Description
Chmoder::chmod() only compares the literal argument against Path::new("/"), so the --preserve-root guard is bypassed by any path that resolves to root — a symlink to / or simply /../.
if self.recursive && self.preserve_root && file == Path::new("/") {
return Err(ChmodError::PreserveRoot("/".to_string()).into());
}
PoC — recursively chmods the entire filesystem to 000 despite --preserve-root:
chmod -R --preserve-root 000 /../ -v
Impact: --preserve-root is the documented safeguard against destructive recursive operations on /. Bypassing it allows chmod -R to alter permissions across the whole filesystem, causing a complete system breakdown. Recommendation: canonicalize the target path before comparing against root.
Remediation: Acknowledged by Canonical; fixed in commit 413055b3.
Reported by Zellic in the uutils coreutils Program Security Assessment (prepared for Canonical, Jan 20 2026), audited commit 3a07ffc5a9bd4c283e75afa548ba1f1957bad242. Finding 3.1. Credit: Zellic.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | uu_chmod | all versions | 0.6.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for uu_chmod. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update uu_chmod to 0.6.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-4c7q-4928-8445 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-4c7q-4928-8445 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-4c7q-4928-8445. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-4c7q-4928-8445 in your dependencies?
O3 detects GHSA-4c7q-4928-8445 across crates.io dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.