CVE-2020-14347

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2020-08-05 · updated 2026-06-17
Weakness: CWE-665

Description

A flaw was found in the way xserver memory was not properly initialized. This could leak parts of server memory to the X client. In cases where Xorg server runs with elevated privileges, this could result in possible ASLR bypass. Xorg-server before version 1.20.9 is vulnerable.

Affected products

Canonical Ubuntu Linux: 14.04, 16.04, 18.04, 20.04
Debian Linux: 9.0, 10.0
xorg-x11-server: before 1.20.9 — fixed in 1.20.9

How to fix

Upgrade to a fixed version: xorg-x11-server 1.20.9. Check the vendor advisory for mitigations.

References

http://lists.opensuse.org/opensuse-security-announce/2020-08/msg00066.html
http://lists.opensuse.org/opensuse-security-announce/2020-08/msg00075.html
https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2020-14347
https://lists.debian.org/debian-lts-announce/2020/08/msg00057.html
https://lists.x.org/archives/xorg-announce/2020-July/003051.html
https://security.gentoo.org/glsa/202012-01
https://usn.ubuntu.com/4488-1/
https://usn.ubuntu.com/4488-2/
https://www.debian.org/security/2020/dsa-4758
https://www.openwall.com/lists/oss-security/2020/07/31/2
http://lists.opensuse.org/opensuse-security-announce/2020-08/msg00066.html
http://lists.opensuse.org/opensuse-security-announce/2020-08/msg00075.html

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