Keycloak: org.keycloak.protocol.oidc.grants.ciba: keycloak: information disclosure via cors header injection due to unvalidated jwt azp claim
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Fix
- Fixed in 26.4.13, 26.6.3
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
- Exploitation: none
- Automatable: no
- Technical impact: partial
Summary
A flaw was found in Keycloak. A remote attacker can exploit a Cross-Origin Resource Sharing (CORS) header injection vulnerability in Keycloak's User-Managed Access (UMA) token endpoint. This flaw occurs because the `azp` claim from a client-supplied JSON Web Token (JWT) is used to set the `Access-Control-Allow-Origin` header before the JWT signature is validated. When a specially crafted JWT with an attacker-controlled `azp` value is processed, this value is reflected as the CORS origin, even if the grant is later rejected. This can lead to the exposure of low-sensitivity information from authorization server error responses, weakening origin isolation, but only when a target client is misconfigured with `webOrigins: ["*"]`.
Timeline
- CVE published
- CISA SSVC assessment
Exploitation: none · Automatable: no · Technical impact: partial
- Record last updated
Affected versions
- rhbk/keycloak-operator-bundle
Version range not reported
- rhbk/keycloak-rhel9
Version range not reported
- rhbk/keycloak-rhel9-operator
Version range not reported
- rhbk/keycloak-rhel9
Version range not reported
- rhbk/keycloak-operator-bundle
Version range not reported
- rhbk/keycloak-rhel9
Version range not reported
- rhbk/keycloak-rhel9-operator
Version range not reported
- rhbk/keycloak-rhel9
Version range not reported
- org.keycloak:keycloak-servicesMaven
fixed in 26.4.13
- org.keycloak:keycloak-servicesMaven
From 26.5.0 · fixed in 26.6.3