CVE-2021-3472

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2021-04-26 · updated 2026-06-17
Weakness: CWE-191

Description

A flaw was found in xorg-x11-server in versions before 1.20.11. An integer underflow can occur in xserver which can lead to a local privilege escalation. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.

Affected products

Debian Linux: 9.0, 10.0
Fedoraproject Fedora: 32, 33, 34
Red Hat Enterprise Linux: 7.0, 8.0
xorg-x11-server: before 1.20.11 — fixed in 1.20.11

How to fix

Upgrade to a fixed version: xorg-x11-server 1.20.11. Check the vendor advisory for mitigations.

References

http://www.openwall.com/lists/oss-security/2021/04/13/1
https://bugzilla.redhat.com/show_bug.cgi?id=1944167
https://gitlab.freedesktop.org/xorg/xserver/-/commit/7aaf54a1884f71dc363f0b884e57bcb67407a6cd
https://lists.debian.org/debian-lts-announce/2021/04/msg00013.html
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/MDF7TAJE7NPZPNVOXSD5HBIFLNPUOD2V/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/MO6S5OPXUDYBSRSVWVLFLJ6AFERG4HNY/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/N63KL3T22HNFT4FJ7VMVF6U5Q4RFJIQF/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PEXPCLMVU25AUZTUXC4MYBGPKOAIM5TW/
https://lists.x.org/archives/xorg-announce/2021-April/003080.html
https://lists.x.org/archives/xorg-announce/2021-April/003080.html
https://lists.x.org/archives/xorg-announce/2021-April/003080.html
https://lists.x.org/archives/xorg-announce/2021-April/003080.html

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