USN-6407-2: libx11 vulnerabilities

10 October 2023

Several security issues were fixed in libx11.

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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
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)

Reduce your security exposure

Ubuntu Pro provides ten-year security coverage to 25,000+ packages in Main and Universe repositories, and it is free for up to five machines.

Learn more about Ubuntu Pro

Update instructions

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

Ubuntu 18.04
Ubuntu 16.04
Ubuntu 14.04

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

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