GHSA-7mqq-6cf9-v2qp
MEDIUMGHSA-7mqq-6cf9-v2qp is a medium-severity (CVSS 5.3) CWE-625 vulnerability in rack. O3 Security confirms whether GHSA-7mqq-6cf9-v2qp is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Rack has a root directory disclosure via unescaped regex interpolation in Rack::Directory
Blast Radius
rack💎rack💎rackReal-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
Summary
Rack::Directory interpolates the configured root path directly into a regular expression when deriving the displayed directory path. If root contains regex metacharacters such as +, *, or ., the prefix stripping can fail and the generated directory listing may expose the full filesystem path in the HTML output.
Details
Rack::Directory::DirectoryBody#each computes the visible path using code equivalent to:
show_path = Utils.escape_html(path.sub(/\A#{root}/, ''))
Here, root is a developer-configured filesystem path. It is normalized earlier with File.expand_path(root) and then inserted directly into a regular expression without escaping.
Because the value is treated as regex syntax rather than as a literal string, metacharacters in the configured path can change how the prefix match behaves. When that happens, the expected root prefix is not removed from path, and the absolute filesystem path is rendered into the HTML directory listing.
Impact
If Rack::Directory is configured to serve a directory whose absolute path contains regex metacharacters, the generated directory listing may disclose the full server filesystem path instead of only the request-relative path.
This can expose internal deployment details such as directory layout, usernames, mount points, or naming conventions that would otherwise not be visible to clients.
Mitigation
- Update to a patched version of Rack in which the root prefix is removed using an escaped regular expression.
- Avoid using
Rack::Directorywith a root path that contains regular expression metacharacters.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 💎RubyGems | rack | all versions | 2.2.23 |
| 💎RubyGems | rack | ≥ 3.0.0.beta1&&< 3.1.21 | 3.1.21 |
| 💎RubyGems | rack | ≥ 3.2.0&&< 3.2.6 | 3.2.6 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for rack. 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 rack to 2.2.23 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-7mqq-6cf9-v2qp 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-7mqq-6cf9-v2qp 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-7mqq-6cf9-v2qp. 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-7mqq-6cf9-v2qp in your dependencies?
O3 detects GHSA-7mqq-6cf9-v2qp across RubyGems dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.