Unsafe client-side session storage leading to authentication bypass/instance takeover via Zabbix Frontend with configured SAML
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Listed in CISA KEV
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
The Zabbix Frontend monitoring software is affected when SAML single sign-on authentication is enabled, which is not the default configuration. An unauthenticated attacker who knows a valid Zabbix username (or uses the disabled-by-default guest account) could tamper with client-side session data to bypass authentication, gain administrator privileges, and take over the Zabbix instance.
Summarized by anthropic/claude-haiku-5.5. Verify details against the original sources.
Read the original 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).
Timeline
- CVE published
- Added to CISA KEV
CISA has evidence of exploitation in the wild
- CISA remediation deadline
Due date for US federal agencies to patch
- Record last updated
- EPSS reached 10%
FIRST estimates at least a 10% chance of exploitation in the next 30 days
Affected versions
- Zabbix Frontend
5.4.0 - 5.4.8