1. Ubuntu Security Notices
  2. USN-5203-1

USN-5203-1: Apache Log4j 2 vulnerability

Publication date

19 December 2021

Overview

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

Releases

Packages

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

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

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

Learn more about how to get the fixes.

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

Ubuntu Release Package Version
21.10 impish liblog4j2-java –  2.17.0-0.21.10.1
21.04 hirsute liblog4j2-java –  2.17.0-0.21.04.1
20.04 focal liblog4j2-java –  2.17.0-0.20.04.1

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References

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