QID 730364

QID 730364: Zabbix Authentication Bypass Vulnerability

Zabbix is an open-source monitoring software tool to monitor IT infrastructure such as networks, servers, virtual machines and cloud services.

In instances where 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. This can lead to authentication bypass/instance takeover via Zabbix Frontend.

Affected Versions:
Zabbix 5.4.0 - 5.4.8
Zabbix 6.0.0alpha1

QID Detection Logic (Unauthenticated):

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).

  • CVSS V3 rated as Critical - 9.8 severity.
  • CVSS V2 rated as Medium - 5.1 severity.
  • Solution

    Vendor has released patch, for more information please refer to ZBX-20350

    Workaround:
    Disable SAML authentication if you can not update to latest version of Zabbix.

    Vendor References

    CVEs related to QID 730364

    Software Advisories
    Advisory ID Software Component Link
    ZBX-20350 URL Logo support.zabbix.com/browse/ZBX-20350