CVE-2019-16777
MEDIUMCVE-2019-16777 is a medium-severity (CVSS 6.5) Path Traversal vulnerability in npm. O3 Security confirms whether CVE-2019-16777 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
npm Vulnerable to Global node_modules Binary Overwrite
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Blast Radius
Weekly download volume for affected packages — a proxy for how broadly this vulnerability is deployed.
npmnpmDescription
Versions of the npm CLI prior to 6.13.4 are vulnerable to an Arbitrary File Overwrite. It fails to prevent existing globally-installed binaries to be overwritten by other package installations. For example, if a package was installed globally and created a serve binary, any subsequent installs of packages that also create a serve binary would overwrite the previous serve binary. This behavior is still allowed in local installations and also through install scripts. This vulnerability bypasses a user using the --ignore-scripts install option.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | npm | all versions | 6.13.4 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for npm. 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 npm to 6.13.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2019-16777 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 CVE-2019-16777 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 CVE-2019-16777. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2019-16777 in your dependencies?
O3 detects CVE-2019-16777 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.