1. Ubuntu Security Notices
  2. USN-6407-2

USN-6407-2: libx11 vulnerabilities

Publication date

10 October 2023

Overview

Several security issues were fixed in libx11.

Releases

Packages

  • libx11 - X11 client-side library

Details

USN-6407-1 fixed several vulnerabilities in libx11. This update provides
the corresponding update for Ubuntu 14.04 LTS, Ubuntu 16.04 LTS and Ubuntu 18.04 LTS.

Original advisory details:

Gregory James Duck discovered that libx11 incorrectly handled certain
keyboard symbols. If a user were tricked into connecting to a malicious X
server, a remote attacker could use this issue to cause libx11 to crash,
resulting in a denial of service, or possibly execute arbitrary code.
(CVE-2023-43785)

Yair Mizrahi discovered that libx11 incorrectly handled certain malformed
XPM image files. If a user were tricked into opening a specially crafted
XPM image file, a remote attacker could possibly use this issue to consume
memory, leading to a denial of service. (CVE-2023-43786)

Yair Mizrahi discovered that libx11 incorrectly handled certain malformed
...

USN-6407-1 fixed several vulnerabilities in libx11. This update provides
the corresponding update for Ubuntu 14.04 LTS, Ubuntu 16.04 LTS and Ubuntu 18.04 LTS.

Original advisory details:

Gregory James Duck discovered that libx11 incorrectly handled certain
keyboard symbols. If a user were tricked into connecting to a malicious X
server, a remote attacker could use this issue to cause libx11 to crash,
resulting in a denial of service, or possibly execute arbitrary code.
(CVE-2023-43785)

Yair Mizrahi discovered that libx11 incorrectly handled certain malformed
XPM image files. If a user were tricked into opening a specially crafted
XPM image file, a remote attacker could possibly use this issue to consume
memory, leading to a denial of service. (CVE-2023-43786)

Yair Mizrahi discovered that libx11 incorrectly handled certain malformed
XPM image files. If a user were tricked into opening a specially crafted
XPM image file, a remote attacker could use this issue to cause libx11 to
crash, leading to a denial of service, or possibly execute arbitrary code.
(CVE-2023-43787)

Update instructions

After a standard system update you need to reboot your computer to make all the necessary changes.

Learn more about how to get the fixes.

The problem can be corrected by updating your system to the following package versions:

Ubuntu Release Package Version
18.04 bionic libx11-6 –  2:1.6.4-3ubuntu0.4+esm2  
16.04 xenial libx11-6 –  2:1.6.3-1ubuntu2.2+esm4  
14.04 trusty libx11-6 –  2:1.6.2-1ubuntu2.1+esm5  

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References

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