An Apache HTTP Server security update has been released for Ubuntu Linux 18.04 LTS, 20.04 LTS, 21.04, and 21.10.

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Ubuntu Security Notice USN-5212-1
January 06, 2022

apache2 vulnerabilities
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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 HTTP Server.

Software Description:
- apache2: Apache HTTP server

Details:

It was discovered that the Apache HTTP Server incorrectly handled certain
forward proxy requests. A remote attacker could use this issue to cause
the server to crash, resulting in a denial of service, or possibly perform
a Server Side Request Forgery attack. (CVE-2021-44224)

It was discovered that the Apache HTTP Server Lua module incorrectly
handled memory in the multipart parser. A remote attacker could use this
issue to cause the server to crash, resulting in a denial of service, or
possibly execute arbitrary code. (CVE-2021-44790)

Update instructions:

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

Ubuntu 21.10:
apache2 2.4.48-3.1ubuntu3.2
apache2-bin 2.4.48-3.1ubuntu3.2

Ubuntu 21.04:
apache2 2.4.46-4ubuntu1.5
apache2-bin 2.4.46-4ubuntu1.5

Ubuntu 20.04 LTS:
apache2 2.4.41-4ubuntu3.9
apache2-bin 2.4.41-4ubuntu3.9

Ubuntu 18.04 LTS:
apache2 2.4.29-1ubuntu4.21
apache2-bin 2.4.29-1ubuntu4.21

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

References:
  https://ubuntu.com/security/notices/USN-5212-1
CVE-2021-44224, CVE-2021-44790

Package Information:
  https://launchpad.net/ubuntu/+source/apache2/2.4.48-3.1ubuntu3.2
  https://launchpad.net/ubuntu/+source/apache2/2.4.46-4ubuntu1.5
  https://launchpad.net/ubuntu/+source/apache2/2.4.41-4ubuntu3.9
  https://launchpad.net/ubuntu/+source/apache2/2.4.29-1ubuntu4.21