CISA adds 2 Zabbix flaws to its Known Exploited Vulnerabilities Catalog
Vulnerabilities mentionedAll →
| CVE | Vulnerability | CVSS | EPSS | Flags | Affected | Exposure | Published |
|---|---|---|---|---|---|---|---|
| CVE-2022-23131 +1 in the same advisory: …23134 | Authentication Bypass via Unverified SAML Session Data in Zabbix Frontend CVE-2022-23131 is a critical (CVSS 9.8) authentication-bypass flaw (CWE-290) in the Zabbix web frontend in which the user login stored in session data is not verified. When SAML SSO authentication is enabled (a non-default configuration), an unauthenticated attacker who can reach the frontend can modify session data to log in as any username they know, including the built-in guest account if it is enabled. By impersonating a known user this way, the attacker escalates privileges and gains admin access to the Zabbix Frontend and the monitoring data and control it provides. Only SAML-enabled deployments are affected, and the attacker must know a valid Zabbix username (or the guest account must be enabled). CISA added the flaw to the Known Exploited Vulnerabilities catalog on 2022-02-22 alongside a second Zabbix flaw, with reports of Zabbix servers under active attack and a 95.7% EPSS probability of exploitation within 30 days; ransomware use is unknown and no public PoC is catalogued. Do: Upgrade Zabbix Frontend to a patched release per the vendor's instructions, as required by CISA's KEV listing; until patched, disable SAML SSO authentication since the bypass requires it, and keep the guest account disabled. Prioritize internet-facing Zabbix frontends and review authentication logs for unauthorized administrator sessions or logins. | 9.8 group max | 96% | KEV |
| largetens of thousands of internet-exposed Zabbix frontends, of which only the non-default SAML-SSO-enabled subset is directly exploitable |
Full article371 words · extracted from securityaffairs.com · click to collapse
Pierluigi Paganini
February 24, 2022
US CISA added two flaws impacting Zabbix infrastructure monitoring tool to its Known Exploited Vulnerabilities Catalog.
US Cybersecurity and Infrastructure Security Agency (CISA) added two new vulnerabilities impacting the Zabbix infrastructure monitoring tool to its Known Exploited Vulnerabilities Catalog.
Threat actors are actively exploiting the two vulnerabilities that are reported in the following table:
| CVE ID | Vulnerability Name | Due Date |
| CVE-2022-23131 | Zabbix Frontend Authentication Bypass Vulnerability | 3/8/2022 |
| CVE-2022-23134 | Zabbix Frontend Improper Access Control Vulnerability | 3/8/2022 |
According to Binding Operational Directive (BOD) 22-01: Reducing the Significant Risk of Known Exploited Vulnerabilities, FCEB agencies have to address the identified vulnerabilities by the due date to protect their networks against attacks exploiting the flaws in the catalog.
Experts recommend also private organizations review the Known Exploited Vulnerabilities Catalog and address the vulnerabilities in their infrastructure.
CISA orders all Federal Civilian Executive Branch Agencies (FCEB) agencies to address both security vulnerabilities in Zabbix by March 2022-03-08.
The first issue, tracked as CVE-2022-23131 (CVSS score: 9.8), is an unsafe client-side session storage that could be exploited to achieve authentication bypass/instance takeover via Zabbix Frontend with configured SAML.
The second flaw, tracked as CVE-2022-23134 (CVSS score: 5.3), could be exploited by threat actors to pass step checks and potentially change the configuration of Zabbix Frontend.
The two flaws affect Zabbix Web Frontend versions up to and including 5.4.8, 5.0.18 and 4.0.36, both issues have been reported by SonarSource researcher Thomas Chauchefoin.
“We discovered a high-severity vulnerability in Zabbix’s implementation of client-side sessions that could lead to the compromise of complete networks.” wrote Chauchefoin.
The issues have since been addressed with the release of versions 5.4.9, 5.0.9 and 4.0.37.
Below is the timeline for both flaws:
| Date | Action |
|---|---|
| 2021-11-18 | A security advisory is sent to Zabbix maintainers. |
| 2021-11-22 | Vendor confirms our findings. |
| 2021-12-14 | A first release candidate, 5.4.9rc1, is issued. |
| 2021-12-14 | We inform the vendor that the patch can be bypassed. |
| 2021-12-22 | A second release candidate, 5.4.9rc2, is released. |
| 2021-12-23 | versions 5.4.9, 5.0.9 and 4.0.37 are released. |
| 2021-12-29 | A public announcement is made at https://support.zabbix.com/browse/ZBX-20350. |
| 2022-01-11 | 6.0.0beta2 is released. |
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Text extracted automatically; images, tables and formatting may be missing. Original: https://securityaffairs.com/128374/hacking/cisa-zabbix-flaws.html