GHSA-m6vc-f87m-cc2h
GHSA-m6vc-f87m-cc2h is a Improper Authentication vulnerability in doorkeeper-openid_connect. O3 Security confirms whether GHSA-m6vc-f87m-cc2h is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Doorkeeper Openid Connect: Dynamic Client Registration feature creates public clients with client_secret
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
Exploitation and automatability from CISA’s SSVC triage for GHSA-m6vc-f87m-cc2h.
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
Impact
The DynamicClientRegistrationController#register action hard-codes confidential: false when creating applications (dynamic_client_registration_controller.rb:18-25), yet the response includes a client_secret and advertises token_endpoint_auth_methods_supported: ["client_secret_basic", "client_secret_post"].
Because Doorkeeper's Application.by_uid_and_secret treats a blank/missing secret as valid for non-confidential (public) clients, an
attacker who knows only the client_id (which is public information) can authenticate as the dynamically-registered client at the token endpoint.
Note that Dynamic Client Registration is opt-in feature which is disabled by default so only projects that explicitly enabled it are affected.
Steps to Reproduce
- Enable dynamic client registration in the initializer
- POST /oauth/registration with client_name, redirect_uris, and scope
- Observe: response returns client_secret, but the created Doorkeeper::Application has confidential: false
- Call
Doorkeeper::Application.by_uid_and_secret(client_id, nil)— it returns the application (credentials bypass) - POST /oauth/token with grant_type=client_credentials and only client_id (no client_secret) — the token endpoint issues an access token without any secret verification
Patches
Patched in 1.10.0
Workarounds
Upgrade existing applications created with a Dynamic Client registration to have confidential: true
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 💎RubyGems | doorkeeper-openid_connect | ≥ 1.9.0&&< 1.10.0 | 1.10.0 |
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 1.10.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-m6vc-f87m-cc2h 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-m6vc-f87m-cc2h 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-m6vc-f87m-cc2h. 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-m6vc-f87m-cc2h in your dependencies?
O3 detects GHSA-m6vc-f87m-cc2h across RubyGems dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.