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Ubuntu Security Notice USN-5222-1
January 11, 2022

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

- Ubuntu 21.10
- Ubuntu 21.04
- Ubuntu 20.04 LTS
- Ubuntu 18.04 LTS

Summary:

Several security issues were fixed in Apache Log4j 2.

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

Details:

It was discovered that Apache Log4j 2 was vulnerable to remote code
execution (RCE) attack when configured to use a JDBC Appender with a
JNDI LDAP data source URI. A remote attacker could possibly use this issue to
cause a crash, leading to a denial of service. (CVE-2021-44832)

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. This issue only affected Ubuntu 18.04 LTS.
(CVE-2021-45105)

Update instructions:

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

Ubuntu 21.10:
  liblog4j2-java                  2.17.1-0.21.10.1

Ubuntu 21.04:
  liblog4j2-java                  2.17.1-0.21.04.1

Ubuntu 20.04 LTS:
  liblog4j2-java                  2.17.1-0.20.04.1

Ubuntu 18.04 LTS:
  liblog4j2-java                  2.12.4-0ubuntu0.1

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

References:
  https://ubuntu.com/security/notices/USN-5222-1
  CVE-2021-44832, CVE-2021-45105

Package Information:
  https://launchpad.net/ubuntu/+source/apache-log4j2/2.17.1-0.21.10.1
  https://launchpad.net/ubuntu/+source/apache-log4j2/2.17.1-0.21.04.1
  https://launchpad.net/ubuntu/+source/apache-log4j2/2.17.1-0.20.04.1
  https://launchpad.net/ubuntu/+source/apache-log4j2/2.12.4-0ubuntu0.1