Описание
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: ["*"].
Ссылки
- Vendor Advisory
- Issue TrackingVendor Advisory
Уязвимые конфигурации
EPSS
3.7 Low
CVSS3
5.3 Medium
CVSS3
Дефекты
Связанные уязвимости
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: ["*"]`.
A flaw was found in Keycloak. A remote attacker can exploit a Cross-Or ...
Keycloak vulnerable to information disclosure via CORS header injection due to unvalidated JWT azp claim
EPSS
3.7 Low
CVSS3
5.3 Medium
CVSS3