GHSA-542g-m3fx-q86f
MEDIUMGHSA-542g-m3fx-q86f is a medium-severity (CVSS 6.5) Improper Authentication vulnerability in org.apache.cxf:cxf-rt-rs-security-oauth2. O3 Security confirms whether GHSA-542g-m3fx-q86f is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Apache CXF has Authentication Bypass in OAuth2 TokenIntrospectionService
Exploitation Status
No confirmed exploitation observed yet
- A successful exploit gives an attacker total control of the affected component, not partial access.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for GHSA-542g-m3fx-q86f.
Real-World Exposure
org.apache.cxf:cxf-rt-rs-security-oauth2☕org.apache.cxf:cxf-rt-rs-security-oauth2Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.
Description
An authentication bypass vulnerability exists in the OAuth2 TokenIntrospectionService in Apache CXF. Due to a missing 'throw' keyword in the security context check, the introspection endpoint (/services/oauth2/introspect) can be accessed by any unauthenticated network attacker. However note that this is a safeguard only in the case that someone forgot to enable authentication on the service. Users are recommended to upgrade to version 4.2.2 or 4.1.7, which fixes this issue.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.apache.cxf:cxf-rt-rs-security-oauth2 | ≥ 4.2.0&&< 4.2.2 | 4.2.2 |
| ☕Maven | org.apache.cxf:cxf-rt-rs-security-oauth2 | all versions | 4.1.7 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.apache.cxf:cxf-rt-rs-security-oauth2. 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 org.apache.cxf:cxf-rt-rs-security-oauth2 to 4.2.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-542g-m3fx-q86f 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-542g-m3fx-q86f 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-542g-m3fx-q86f. 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-542g-m3fx-q86f in your dependencies?
O3 detects GHSA-542g-m3fx-q86f across Maven dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.