USN-5638-3: Expat vulnerability

USN-5638-1 fixed a vulnerability in Expat. This update provides
the corresponding updates for Ubuntu 16.04 ESM, Ubuntu 18.04 LTS,
Ubuntu 20.04 LTS, Ubuntu 22.04 LTS and Ubuntu 22.10. (CVE-2022-43680)
This update also fixes a minor regression introduced in
Ubuntu 18.04 LTS.

We apologize for the inconvenience.

Original advisory details:

Rhodri James discovered that Expat incorrectly handled memory when
processing certain malformed XML files. An attacker could possibly
use this issue to cause a crash or execute arbitrary code.

expat usn vulnerability