A kramdown security update has been released for Ubuntu Linux 20.04 LTS.

[USN-6424-1] kramdown vulnerability

==========================================================================
Ubuntu Security Notice USN-6424-1
October 10, 2023

ruby-kramdown vulnerability
==========================================================================

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

- Ubuntu 20.04 LTS

Summary:

kramdown could be made to execute arbitrary code if it received specially
crafted input.

Software Description:
- ruby-kramdown: Fast, pure-Ruby Markdown-superset converter - ruby library

Details:

It was discovered that kramdown did not restrict Rouge formatters to the
correct namespace. An attacker could use this issue to cause kramdown to
execute arbitrary code.

Update instructions:

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

Ubuntu 20.04 LTS:
ruby-kramdown 1.17.0-4ubuntu0.2

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

References:
https://ubuntu.com/security/notices/USN-6424-1
CVE-2021-28834

Package Information:
https://launchpad.net/ubuntu/+source/ruby-kramdown/1.17.0-4ubuntu0.2