An Apache HTTP security update has been released for Ubuntu Linux 14.04 ESM and 16.04 ESM.

USN-5212-2: Apache HTTP Server vulnerabilities

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Ubuntu Security Notice USN-5212-2
January 10, 2022

apache2 vulnerabilities
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A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 16.04 ESM
- Ubuntu 14.04 ESM

Summary:

Several security issues were fixed in Apache HTTP Server.

Software Description:
- apache2: Apache HTTP server

Details:

USN-5212-1 fixed several vulnerabilities in Apache. This update provides
the corresponding update for Ubuntu 14.04 ESM and Ubuntu 16.04 ESM.

Original advisory 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 16.04 ESM:
apache2 2.4.18-2ubuntu3.17+esm4
apache2-bin 2.4.18-2ubuntu3.17+esm4

Ubuntu 14.04 ESM:
apache2 2.4.7-1ubuntu4.22+esm3
apache2-bin 2.4.7-1ubuntu4.22+esm3

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

References:
  https://ubuntu.com/security/notices/USN-5212-2
  https://ubuntu.com/security/notices/USN-5212-1
CVE-2021-44224, CVE-2021-44790