A Expat security update has been released for Ubuntu 18.04 LTS, 20.04 LTS, and 22.04 LTS.

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Ubuntu Security Notice USN-5638-2
November 17, 2022

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

- Ubuntu 22.04 LTS
- Ubuntu 20.04 LTS
- Ubuntu 18.04 LTS

Summary:

Expat could be made to crash or execute arbitrary code.

Software Description:
- expat: XML parsing C library

Details:

USN-5638-1 fixed a vulnerability in Expat. This update provides
the corresponding updates for Ubuntu 18.04 LTS, Ubuntu 20.04 LTS and
Ubuntu 22.04 LTS.

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.

Update instructions:

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

Ubuntu 22.04 LTS:
expat 2.4.7-1ubuntu0.1
libexpat1 2.4.7-1ubuntu0.1

Ubuntu 20.04 LTS:
expat 2.2.9-1ubuntu0.5
libexpat1 2.2.9-1ubuntu0.5

Ubuntu 18.04 LTS:
expat 2.2.5-3ubuntu0.8
libexpat1 2.2.5-3ubuntu0.8

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

References:
https://ubuntu.com/security/notices/USN-5638-2
https://ubuntu.com/security/notices/USN-5638-1
CVE-2022-40674, CVE-2022-43680

Package Information:
https://launchpad.net/ubuntu/+source/expat/2.4.7-1ubuntu0.1
https://launchpad.net/ubuntu/+source/expat/2.2.9-1ubuntu0.5
https://launchpad.net/ubuntu/+source/expat/2.2.5-3ubuntu0.8