CVE-2022-23131
Description
In the case of instances where the SAML SSO authentication is enabled (non-default), session data can be modified by a malicious actor, because a user login stored in the session was not verified. Malicious unauthenticated actor may exploit this issue to escalate privileges and gain admin access to Zabbix Frontend. To perform the attack, SAML authentication is required to be enabled and the actor has to know the username of Zabbix user (or use the guest account, which is disabled by default).
Summary dbcve.org
In Zabbix Frontend instances with SAML SSO authentication enabled, session data containing a user login is not cryptographically verified, allowing an unauthenticated attacker who knows (or can guess) a valid username to forge or tamper with session information and escalate to admin-level access. Exploitation requires only that SAML SSO be enabled and knowledge of a valid Zabbix username (the default 'guest' account is disabled by default, reducing trivial exploitation).
Mitigation
Upgrade Zabbix to a patched version (5.4.9 / 6.0.1 / 6.0.2 or later as applicable) that verifies session integrity under SAML SSO; if upgrade is not immediately possible, disable SAML SSO authentication as a temporary mitigation and audit Zabbix Frontend logs for signs of prior exploitation.