GHSA-hrqr-hxpp-chr3 is a medium-severity (CVSS 6.3) vulnerability in rack. O3 Security confirms whether GHSA-hrqr-hxpp-chr3 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Possible Information Leak / Session Hijack Vulnerability in Rack
Real-World Exposure
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
There's a possible information leak / session hijack vulnerability in Rack. Attackers may be able to find and hijack sessions by using timing attacks targeting the session id. Session ids are usually stored and indexed in a database that uses some kind of scheme for speeding up lookups of that session id. By carefully measuring the amount of time it takes to look up a session, an attacker may be able to find a valid session id and hijack the session.
The session id itself may be generated randomly, but the way the session is indexed by the backing store does not use a secure comparison.
Impact
The session id stored in a cookie is the same id that is used when querying the backing session storage engine. Most storage mechanisms (for example a database) use some sort of indexing in order to speed up the lookup of that id. By carefully timing requests and session lookup failures, an attacker may be able to perform a timing attack to determine an existing session id and hijack that session.
Releases
The 1.6.12 and 2.0.8 releases are available at the normal locations.
Workarounds
There are no known workarounds.
Patches
To aid users who aren't able to upgrade immediately we have provided patches for the two supported release series. They are in git-am format and consist of a single changeset.
- 1-6-session-timing-attack.patch - Patch for 1.6 series
- 2-0-session-timing-attack.patch - Patch for 2.6 series
Credits
Thanks Will Leinweber for reporting this!
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 💎RubyGems | rack | all versions | 1.6.12 |
| 💎RubyGems | rack | ≥ 2.0.0&&< 2.0.8 | 2.0.8 |
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 1.6.12 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-hrqr-hxpp-chr3 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-hrqr-hxpp-chr3 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-hrqr-hxpp-chr3. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
Because Red Hat OpenStack Platform 13.0 Operational Tools packaged the flawed code, but does not use its functionality, its Impact has been reduced to 'Low'.
Frequently Asked Questions
Is GHSA-hrqr-hxpp-chr3 in your dependencies?
O3 detects GHSA-hrqr-hxpp-chr3 across RubyGems dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.