In Zabbix from 4.0.x before 4.0.28rc1, 5.0.0alpha1 before 5.0.10rc1, 5.2.x before…
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- Required
- Attack complexity
- Low
- Impact type
- Tampering
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-352.
Summary
In Zabbix from 4.0.x before 4.0.28rc1, 5.0.0alpha1 before 5.0.10rc1, 5.2.x before 5.2.6rc1, and 5.4.0alpha1 before 5.4.0beta2, the CControllerAuthenticationUpdate controller lacks a CSRF protection mechanism. The code inside this controller calls diableSIDValidation inside the init() method. An attacker doesn't have to know Zabbix user login credentials, but has to know the correct Zabbix URL and contact information of an existing user with sufficient privileges.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
Remediation
No fixed version listed by the sources yet.
Vendor assessments
Timeline
- 2026-10-02 Threatist record created from CVE-2021-27927
- 2026-10-03 Alias added: GHSA-3mh6-r7m6-r42x
References
More Zabbix vulnerabilities
- TI-2022-07300 Authentication bypass by spoofing in Zabbix Frontend KEVCVSS 3.1CRITICAL 9.8
- TI-2024-28315 SQL injection in user.get API CVSS 3.1CRITICAL 9.9
- TI-2016-08210 SQL injection vulnerability in Zabbix before 2.2.14 and 3.0 before 3.0.4 allows remote… CVSS 3.0CRITICAL 9.8
- TI-2013-04884 Multiple SQL injection vulnerabilities in Zabbix 1.8.x before 1.8.18rc1, 2.0.x before 2.0.9rc1, and 2.1.x before 2.1.7. CVSS 3.1CRITICAL 9.8
- TI-2022-07303 Possible view of the setup pages by unauthenticated users if config file already exists KEVCVSS 3.1MEDIUM 5.3
- TI-2024-14721 Time Based SQL Injection in Zabbix Server Audit Log CVSS 3.1CRITICAL 9.1
Sources
- CVE-2021-27927 · CVE Program
- CVE-2021-27927 · NVD
- FIRST EPSS
- GHSA-3mh6-r7m6-r42x · GitHub Advisory Database · CC BY 4.0
- CVE-2021-27927 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences