CVE-2020-14363

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.6% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2020-09-11 · updated 2026-06-17
Weakness: CWE-190

Description

An integer overflow vulnerability leading to a double-free was found in libX11. This flaw allows a local privileged attacker to cause an application compiled with libX11 to crash, or in some cases, result in arbitrary code execution. The highest threat from this flaw is to confidentiality, integrity as well as system availability.

Affected products

Fedoraproject Fedora: 33
x.org libX11: before 1.6.12 — fixed in 1.6.12

How to fix

Upgrade to a fixed version: x.org libX11 1.6.12. Check the vendor advisory for mitigations.

References

https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2020-14363
https://github.com/Ruia-ruia/Exploits/blob/master/DFX11details.txt
https://github.com/Ruia-ruia/Exploits/blob/master/x11doublefree.sh
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/7AVXCQOSCAPKYYHFIJAZ6E2C7LJBTLXF/
https://lists.x.org/archives/xorg-announce/2020-August/003056.html
https://usn.ubuntu.com/4487-2/
https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2020-14363
https://github.com/Ruia-ruia/Exploits/blob/master/DFX11details.txt
https://github.com/Ruia-ruia/Exploits/blob/master/x11doublefree.sh
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/7AVXCQOSCAPKYYHFIJAZ6E2C7LJBTLXF/
https://lists.x.org/archives/xorg-announce/2020-August/003056.html
https://usn.ubuntu.com/4487-2/

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