title: Unsafe client-side session storage leading to authentication bypass/instance takeover via Zabbix Frontend with configured SAML
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).
problem types: CWE-290 Authentication Bypass by Spoofing
affected:
{
product: Frontend
vendor: Zabbix
versions:
status: affected, version: 5.4.0 - 5.4.8
lessThan: 5.4.9*, status: unaffected, version: 5.4.9, versionType: custom
}
metrics:
cvssV3_1: [
attackComplexity: LOW
attackVector: NETWORK
availabilityImpact: NONE
baseScore: 9.1
baseSeverity: CRITICAL
confidentialityImpact: HIGH
integrityImpact: HIGH
privilegesRequired: NONE
scope: UNCHANGED
userInteraction: NONE
vectorString: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
version: 3.1
]
solutions: To remediate this vulnerability, install the updates or if an immediate update is not possible, follow the presented workarounds.
workarounds: Disable SAML authentication