CVE-2017-12185

Severity: critical (CVSS 9.8 v3.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 4.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2018-01-24 · updated 2026-06-17
Weakness: CWE-391

Description

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

Affected products

Debian Linux: 8.0, 9.0
xorg-x11-server: before 1.19.5 — fixed in 1.19.5

How to fix

Upgrade to a fixed version: xorg-x11-server 1.19.5. Check the vendor advisory for mitigations.

References

https://bugzilla.redhat.com/show_bug.cgi?id=1509215
https://cgit.freedesktop.org/xorg/xserver/commit/?id=cad5a1050b7184d828aef9c1dd151c3ab649d37e
https://lists.debian.org/debian-lts-announce/2017/11/msg00032.html
https://www.debian.org/security/2017/dsa-4000
https://bugzilla.redhat.com/show_bug.cgi?id=1509215
https://cgit.freedesktop.org/xorg/xserver/commit/?id=cad5a1050b7184d828aef9c1dd151c3ab649d37e
https://lists.debian.org/debian-lts-announce/2017/11/msg00032.html
https://www.debian.org/security/2017/dsa-4000

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