CVE-2020-14363 Use after free in libX11

High 7.8 Published Updated

A local privileged attacker can exploit an integer overflow leading to a double-free in libX11 to crash applications or execute arbitrary code.

Exploited in the wild
Not known
Login needed
Any signed-in user
Attackable
Local or same network only
Victim action needed
Not needed
Fix
Available

What is CVE-2020-14363?

CVE-2020-14363 is a high-severity use after free vulnerability in Fedoraproject Fedora, published on 11 Sep 2020. It can only be exploited from the same machine or local network, with no action from the victim.

Official 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.

Weakness: CWE-416, CWE-190

Which versions are affected by CVE-2020-14363?

It affects 2 products.

Linux distribution packages (40)
libX11 Red Hat:enterprise_linux:6::clientAll versions0:1.6.4-4.el6_10
libX11-common Red Hat:enterprise_linux:6::clientAll versions0:1.6.4-4.el6_10
libX11-debuginfo Red Hat:enterprise_linux:6::clientAll versions0:1.6.4-4.el6_10
libX11-devel Red Hat:enterprise_linux:6::clientAll versions0:1.6.4-4.el6_10
libX11 Red Hat:enterprise_linux:6::computenodeAll versions0:1.6.4-4.el6_10
libX11-common Red Hat:enterprise_linux:6::computenodeAll versions0:1.6.4-4.el6_10
libX11-debuginfo Red Hat:enterprise_linux:6::computenodeAll versions0:1.6.4-4.el6_10
libX11-devel Red Hat:enterprise_linux:6::computenodeAll versions0:1.6.4-4.el6_10
libX11 Red Hat:enterprise_linux:6::serverAll versions0:1.6.4-4.el6_10
libX11-common Red Hat:enterprise_linux:6::serverAll versions0:1.6.4-4.el6_10
libX11-debuginfo Red Hat:enterprise_linux:6::serverAll versions0:1.6.4-4.el6_10
libX11-devel Red Hat:enterprise_linux:6::serverAll versions0:1.6.4-4.el6_10
libX11 Red Hat:enterprise_linux:6::workstationAll versions0:1.6.4-4.el6_10
libX11-common Red Hat:enterprise_linux:6::workstationAll versions0:1.6.4-4.el6_10
libX11-debuginfo Red Hat:enterprise_linux:6::workstationAll versions0:1.6.4-4.el6_10
libX11-devel Red Hat:enterprise_linux:6::workstationAll versions0:1.6.4-4.el6_10
libX11 Red Hat:enterprise_linux:7::clientAll versions0:1.6.7-3.el7_9
libX11-common Red Hat:enterprise_linux:7::clientAll versions0:1.6.7-3.el7_9
libX11-debuginfo Red Hat:enterprise_linux:7::clientAll versions0:1.6.7-3.el7_9
libX11-devel Red Hat:enterprise_linux:7::clientAll versions0:1.6.7-3.el7_9
libX11-debuginfo Red Hat:enterprise_linux:7::computenodeAll versions0:1.6.7-3.el7_9
libX11-devel Red Hat:enterprise_linux:7::computenodeAll versions0:1.6.7-3.el7_9
libX11 Red Hat:enterprise_linux:7::serverAll versions0:1.6.7-3.el7_9
libX11-common Red Hat:enterprise_linux:7::serverAll versions0:1.6.7-3.el7_9
libX11-debuginfo Red Hat:enterprise_linux:7::serverAll versions0:1.6.7-3.el7_9
libX11-devel Red Hat:enterprise_linux:7::serverAll versions0:1.6.7-3.el7_9
libX11 Red Hat:enterprise_linux:7::workstationAll versions0:1.6.7-3.el7_9
libX11-common Red Hat:enterprise_linux:7::workstationAll versions0:1.6.7-3.el7_9
libX11-debuginfo Red Hat:enterprise_linux:7::workstationAll versions0:1.6.7-3.el7_9
libX11-devel Red Hat:enterprise_linux:7::workstationAll versions0:1.6.7-3.el7_9
libX11 SUSE:Enterprise Storage 5All versions1.6.2-12.15.1
libX11 SUSE:HPE Helion OpenStack 8All versions1.6.2-12.15.1
libX11 SUSE:Linux Enterprise High Performance Computing 15-ESPOSAll versions1.6.5-3.12.1
libX11 SUSE:Linux Enterprise High Performance Computing 15-LTSSAll versions1.6.5-3.12.1
libX11 SUSE:Linux Enterprise Module for Basesystem 15 SP1All versions1.6.5-3.12.1
libX11 SUSE:Linux Enterprise Module for Basesystem 15 SP2All versions1.6.5-3.12.1
libX11 SUSE:Linux Enterprise Server 12 SP2-BCLAll versions1.6.2-12.15.1
libX11 SUSE:Linux Enterprise Server 12 SP2-LTSSAll versions1.6.2-12.15.1
libX11 SUSE:Linux Enterprise Server 12 SP3-BCLAll versions1.6.2-12.15.1
libX11 SUSE:Linux Enterprise Server 12 SP3-LTSSAll versions1.6.2-12.15.1

Products include Fedoraproject Fedora, X.org Libx11.

How do I fix CVE-2020-14363?

Apply the vendor's patch.

Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.

Is CVE-2020-14363 being exploited?

There is no known exploitation of CVE-2020-14363 in the wild and no public exploit code.

All Fedoraproject Fedora vulnerabilities

Sources

Also known as ALPINE-CVE-2020-14363, DEBIAN-CVE-2020-14363, DLA-2361-1, GHSA-qmwg-hw9q-xg39, JLSEC-2026-470, MGASA-2020-0349 and 9 more.

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