Ubuntu 21.04 USN-4994-1 Critical: Apache HTTP Server Denial of Service

ubuntu

June 21, 2021

Several security issues were fixed in Apache HTTP Server.

Summary

Several security issues were fixed in Apache HTTP Server.

Software Description:

- apache2: Apache HTTP server

Details:

Marc Stern discovered that the Apache mod_proxy_http module incorrectly

handled certain requests. A remote attacker could possibly use this issue

to cause Apache to crash, resulting in a denial of service. This issue only

affected Ubuntu 20.04 LTS, Ubuntu 20.10, and Ubuntu 21.04. (CVE-2020-13950)

Antonio Morales discovered that the Apache mod_auth_digest module

incorrectly handled certain Digest nonces. A remote attacker could possibly

use this issue to cause Apache to crash, resulting in a denial of service.

(CVE-2020-35452)

Antonio Morales discovered that the Apache mod_session module incorrectly

handled certain Cookie headers. A remote attacker could possibly use this

issue to cause Apache to crash, resulting in a denial of service.

(CVE-2021-26690)

Christophe Jaillet discovered that the Apache mod_session module

incorrectly handled...

Read the Full Advisory

Topics Covered

security advisory denial of service security issue update Ubuntu Apache

Update Instructions

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

Ubuntu 21.04:
  apache2                         2.4.46-4ubuntu1.1
  apache2-bin                     2.4.46-4ubuntu1.1

Ubuntu 20.10:
  apache2                         2.4.46-1ubuntu1.2
  apache2-bin                     2.4.46-1ubuntu1.2

Ubuntu 20.04 LTS:
  apache2                         2.4.41-4ubuntu3.3
  apache2-bin                     2.4.41-4ubuntu3.3

Ubuntu 18.04 LTS:
  apache2                         2.4.29-1ubuntu4.16
  apache2-bin                     2.4.29-1ubuntu4.16

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