CVE-2019-9837 is a medium-severity (CVSS 6.1) Open Redirect vulnerability in doorkeeper-openid_connect. O3 Security confirms whether CVE-2019-9837 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Doorkeeper-openid_connect contains Open Redirect
Real-World Exposure
doorkeeper-openid_connectReal-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
Doorkeeper::OpenidConnect (aka the OpenID Connect extension for Doorkeeper) 1.4.x and 1.5.x before 1.5.4 has an open redirect via the redirect_uri field in an OAuth authorization request (that results in an error response) with the 'openid' scope and a prompt=none value. This allows phishing attacks against the authorization flow.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 💎RubyGems | doorkeeper-openid_connect | ≥ 1.4.0&&< 1.5.4 | 1.5.4 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for doorkeeper-openid_connect. 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 doorkeeper-openid_connect to 1.5.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2019-9837 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-2019-9837 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-2019-9837. 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-2019-9837 in your dependencies?
O3 detects CVE-2019-9837 across RubyGems dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.