USN-4994-2: Apache HTTP Server vulnerabilities
21 June 2021
Several security issues were fixed in Apache HTTP Server.
Releases
Packages
- apache2 - Apache HTTP server
Details
USN-4994-1 fixed several vulnerabilities in Apache. This update provides
the corresponding update for Ubuntu 14.04 ESM and Ubuntu 16.04 ESM.
Original advisory details:
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 certain SessionHeader values. A remote attacker could
use this issue to cause Apache to crash, resulting in a denial of service,
or possibly execute arbitrary code. (CVE-2021-26691)
Christoph Anton Mitterer discovered that the new MergeSlashes configuration
option resulted in unexpected behaviour in certain situations.
(CVE-2021-30641)
Update instructions
The problem can be corrected by updating your system to the following package versions:
Ubuntu 16.04
-
apache2
-
2.4.18-2ubuntu3.17+esm1
Available with Ubuntu Pro
-
apache2-bin
-
2.4.18-2ubuntu3.17+esm1
Available with Ubuntu Pro
Ubuntu 14.04
-
apache2
-
2.4.7-1ubuntu4.22+esm1
Available with Ubuntu Pro
-
apache2-bin
-
2.4.7-1ubuntu4.22+esm1
Available with Ubuntu Pro
In general, a standard system update will make all the necessary changes.