An Apache HTTP Server security update has been released for Ubuntu Linux 14.04 LTS, 16.04 LTS, and 18.04 LTS.

[USN-6510-1] Apache HTTP Server vulnerability

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Ubuntu Security Notice USN-6510-1
November 23, 2023

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

- Ubuntu 18.04 LTS (Available with Ubuntu Pro)
- Ubuntu 16.04 LTS (Available with Ubuntu Pro)
- Ubuntu 14.04 LTS (Available with Ubuntu Pro)

Summary:

Apache HTTP Server could be made to crash if it received a specially
crafted request.

Software Description:
- apache2: Apache HTTP server

Details:

David Shoon discovered that the Apache HTTP Server mod_macro module
incorrectly handled certain memory operations. A remote attacker could
possibly use this issue to cause the server to crash, resulting in a denial
of service.

Update instructions:

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

Ubuntu 18.04 LTS (Available with Ubuntu Pro):
  apache2                         2.4.29-1ubuntu4.27+esm1

Ubuntu 16.04 LTS (Available with Ubuntu Pro):
  apache2                         2.4.18-2ubuntu3.17+esm11

Ubuntu 14.04 LTS (Available with Ubuntu Pro):
  apache2                         2.4.7-1ubuntu4.22+esm9

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

References:
  https://ubuntu.com/security/notices/USN-6510-1
  CVE-2023-31122