CVE-2017-17042 is a high-severity (CVSS 7.5) Path Traversal vulnerability in yard. O3 Security confirms whether CVE-2017-17042 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Arbitrary file read vulnerability in yard server
Real-World Exposure
yardReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects RubyGems packages — download data is not available via public APIs for these ecosystems.
Description
lib/yard/core_ext/file.rb in the server in YARD before 0.9.11 does not block relative paths with an initial ../ sequence, which allows attackers to conduct directory traversal attacks and read arbitrary files.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 💎RubyGems | yard | all versions | 0.9.11 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for yard. 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 yard to 0.9.11 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2017-17042 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-2017-17042 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-2017-17042. 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-2017-17042 in your dependencies?
O3 detects CVE-2017-17042 across RubyGems dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.