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Ubuntu Security Notice USN-6407-1
October 03, 2023
libx11 vulnerabilities
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A security issue affects these releases of Ubuntu and its derivatives:
- Ubuntu 23.04
- Ubuntu 22.04 LTS
- Ubuntu 20.04 LTS
Summary:
Several security issues were fixed in libx11.
Software Description:
- libx11: X11 client-side library
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:
The problem can be corrected by updating your system to the following
package versions:
Ubuntu 23.04:
   libx11-6                        2:1.8.4-2ubuntu0.3
Ubuntu 22.04 LTS:
   libx11-6                        2:1.7.5-1ubuntu0.3
Ubuntu 20.04 LTS:
   libx11-6                        2:1.6.9-2ubuntu1.6
After a standard system update you need to reboot your computer to make all
the necessary changes.
References:
   https://ubuntu.com/security/notices/USN-6407-1
   CVE-2023-43785, CVE-2023-43786, CVE-2023-43787
Package Information:
   https://launchpad.net/ubuntu/+source/libx11/2:1.8.4-2ubuntu0.3
   https://launchpad.net/ubuntu/+source/libx11/2:1.7.5-1ubuntu0.3
   https://launchpad.net/ubuntu/+source/libx11/2:1.6.9-2ubuntu1.6