GHSA-wq4h-7r42-5hrr
CRITICALPossible shell escape sequence injection vulnerability in Rack
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
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
There is a possible shell escape sequence injection vulnerability in the Lint and CommonLogger components of Rack. This vulnerability has been assigned the CVE identifier CVE-2022-30123.
Versions Affected: All. Not affected: None Fixed Versions: 2.0.9.1, 2.1.4.1, 2.2.3.1
Impact
Carefully crafted requests can cause shell escape sequences to be written to the terminal via Rack's Lint middleware and CommonLogger middleware. These escape sequences can be leveraged to possibly execute commands in the victim's terminal.
Impacted applications will have either of these middleware installed, and vulnerable apps may have something like this:
use Rack::Lint
Or
use Rack::CommonLogger
All users running an affected release should either upgrade or use one of the workarounds immediately.
Workarounds
Remove these middleware from your application
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 💎RubyGems | rack | all versions | 2.0.9.1 |
| 💎RubyGems | rack | ≥ 2.1&&< 2.1.4.1 | 2.1.4.1 |
| 💎RubyGems | rack | ≥ 2.2&&< 2.2.3.1 | 2.2.3.1 |
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 2.0.9.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-wq4h-7r42-5hrr 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-wq4h-7r42-5hrr 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-wq4h-7r42-5hrr. 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-wq4h-7r42-5hrr in your dependencies?
O3 detects GHSA-wq4h-7r42-5hrr across RubyGems dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.