What’s Vulnerable › Vulnerabilities

CVE-2017-12178

• Severity: critical (CVSS 9.8 v3.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 4.4% 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 had wrong extra length check in ProcXIChangeHierarchy function 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=1509219
• https://cgit.freedesktop.org/xorg/xserver/commit/?id=859b08d523307eebde7724fd1a0789c44813e821
• https://lists.debian.org/debian-lts-announce/2017/11/msg00032.html
• https://security.gentoo.org/glsa/201711-05
• https://www.debian.org/security/2017/dsa-4000
• https://bugzilla.redhat.com/show_bug.cgi?id=1509219
• https://cgit.freedesktop.org/xorg/xserver/commit/?id=859b08d523307eebde7724fd1a0789c44813e821
• https://lists.debian.org/debian-lts-announce/2017/11/msg00032.html
• https://security.gentoo.org/glsa/201711-05
• https://www.debian.org/security/2017/dsa-4000

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