A flaw was found in the offline_access scope in Keycloak. This issue would affect users of shared computers more (especially if cookies are not cleared), due to a lack of root session validation, and the reuse of session ids across root and user authentication sessions. This enables an attacker to resolve a user session attached to a previously authenticated user; when utilizing the refresh token, they will be issued a token for the original user.
Authenticating a user, or otherwise establishing a new user session, without invalidating any existing session identifier gives an attacker the opportunity to steal authenticated sessions.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Keycloak | Redhat | * | 20.0.2 (excluding) |
| Single_sign-on | Redhat | - (including) | - (including) |
| Red Hat Single Sign-On 7 | RedHat | rh-sso7-keycloak | * |
| Red Hat Single Sign-On 7.6.1 | RedHat | rh-sso7-keycloak | * |
| Red Hat Single Sign-On 7.6 for RHEL 7 | RedHat | rh-sso7-keycloak-0:18.0.3-1.redhat_00002.1.el7sso | * |
| Red Hat Single Sign-On 7.6 for RHEL 7 | RedHat | rh-sso7-keycloak-0:18.0.6-1.redhat_00001.1.el7sso | * |
| Red Hat Single Sign-On 7.6 for RHEL 8 | RedHat | rh-sso7-keycloak-0:18.0.3-1.redhat_00002.1.el8sso | * |
| Red Hat Single Sign-On 7.6 for RHEL 8 | RedHat | rh-sso7-keycloak-0:18.0.6-1.redhat_00001.1.el8sso | * |
| Red Hat Single Sign-On 7.6 for RHEL 9 | RedHat | rh-sso7-keycloak-0:18.0.3-1.redhat_00002.1.el9sso | * |
| Red Hat Single Sign-On 7.6 for RHEL 9 | RedHat | rh-sso7-keycloak-0:18.0.6-1.redhat_00001.1.el9sso | * |
| RHEL-8 based Middleware Containers | RedHat | rh-sso-7/sso76-openshift-rhel8:7.6-15 | * |
| RHEL-8 based Middleware Containers | RedHat | rh-sso-7/sso76-openshift-rhel8:7.6-20 | * |
Such a scenario is commonly observed when:
In the generic exploit of session fixation vulnerabilities, an attacker creates a new session on a web application and records the associated session identifier. The attacker then causes the victim to associate, and possibly authenticate, against the server using that session identifier, giving the attacker access to the user’s account through the active session.