A Ghostscript security update has been released for Ubuntu Linux 18.04 LTS, 20.04 LTS, 21.04, and 21.10.

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Ubuntu Security Notice USN-5224-1
January 12, 2022

ghostscript vulnerabilities
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A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 21.10
- Ubuntu 21.04
- Ubuntu 20.04 LTS
- Ubuntu 18.04 LTS

Summary:

Several security issues were fixed in Ghostscript.

Software Description:
- ghostscript: PostScript and PDF interpreter

Details:

It was discovered that Ghostscript incorrectly handled certain PostScript
files. If a user or automated system were tricked into processing a
specially crafted file, a remote attacker could possibly use this issue to
cause Ghostscript to crash, resulting in a denial of service, or possibly
execute arbitrary code.

Update instructions:

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

Ubuntu 21.10:
ghostscript 9.54.0~dfsg1-0ubuntu2.1
libgs9 9.54.0~dfsg1-0ubuntu2.1

Ubuntu 21.04:
ghostscript 9.53.3~dfsg-7ubuntu0.2
libgs9 9.53.3~dfsg-7ubuntu0.2

Ubuntu 20.04 LTS:
ghostscript 9.50~dfsg-5ubuntu4.5
libgs9 9.50~dfsg-5ubuntu4.5

Ubuntu 18.04 LTS:
ghostscript 9.26~dfsg+0-0ubuntu0.18.04.15
libgs9 9.26~dfsg+0-0ubuntu0.18.04.15

In general, a standard system update will make all the necessary changes.

References:
  https://ubuntu.com/security/notices/USN-5224-1
CVE-2021-45944, CVE-2021-45949

Package Information:
  https://launchpad.net/ubuntu/+source/ghostscript/9.54.0~dfsg1-0ubuntu2.1
  https://launchpad.net/ubuntu/+source/ghostscript/9.53.3~dfsg-7ubuntu0.2
  https://launchpad.net/ubuntu/+source/ghostscript/9.50~dfsg-5ubuntu4.5
  https://launchpad.net/ubuntu/+source/ghostscript/9.26~dfsg+0-0ubuntu0.18.04.15