=========================================================================Ubuntu Security Notice USN-5197-1
December 15, 2021

apache-log4j2 vulnerability
=========================================================================
A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 21.10
- Ubuntu 21.04
- Ubuntu 20.04 LTS

Summary:

Apache Log4j 2 could be made to crash if it received specially crafted input.

Software Description:
- apache-log4j2: Apache Log4j - Logging Framework for Java

Details:

It was found that the fix to address CVE-2021-44228 in Apache Log4j 2.15.0 was
incomplete in certain non-default configurations. An attacker could use this
vulnerability to cause a denial of service.

Update instructions:

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

Ubuntu 21.10:
  liblog4j2-java                  2.16.0-0.21.10.1

Ubuntu 21.04:
  liblog4j2-java                  2.16.0-0.21.04.1

Ubuntu 20.04 LTS:
  liblog4j2-java                  2.16.0-0.20.04.1

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

References:
  https://ubuntu.com/security/notices/USN-5197-1
  CVE-2021-44228, CVE-2021-45046

Package Information:
  https://launchpad.net/ubuntu/+source/apache-log4j2/2.16.0-0.21.10.1
  https://launchpad.net/ubuntu/+source/apache-log4j2/2.16.0-0.21.04.1
  https://launchpad.net/ubuntu/+source/apache-log4j2/2.16.0-0.20.04.1