USN-5203-1: Apache Log4j 2 vulnerability

Releases

• Ubuntu 21.10
• Ubuntu 21.04
• Ubuntu 20.04 LTS

Packages

• apache-log4j2 - Apache Log4j - Logging Framework for Java

Details

Hideki Okamoto and Guy Lederfein discovered that Apache Log4j 2 did not
protect against infinite recursion in lookup evaluation. A remote attacker
could possibly use this issue to cause Apache Log4j 2 to crash, leading to
a denial of service.
Please see the following link for more information:
https://wiki.ubuntu.com/SecurityTeam/KnowledgeBase/Log4Shell

Update instructions

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

Ubuntu 21.10

• liblog4j2-java - 2.17.0-0.21.10.1

Ubuntu 21.04

• liblog4j2-java - 2.17.0-0.21.04.1

Ubuntu 20.04

• liblog4j2-java - 2.17.0-0.20.04.1

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

References

• CVE-2021-45105

Related notices

• USN-5222-1: apache-log4j2, liblog4j2-java, liblog4j2-java-doc