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.
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
Source: MITRE
Published: 2018-01-24
Updated: 2019-10-09
Type: CWE-20
Base Score: 7.5
Vector: AV:N/AC:L/Au:N/C:P/I:P/A:P
Impact Score: 6.4
Exploitability Score: 10
Severity: HIGH
Base Score: 9.8
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Impact Score: 5.9
Exploitability Score: 3.9
Severity: CRITICAL