USN-4994-1: Apache HTTP Server vulnerabilities
21 June 2021
Several security issues were fixed in Apache HTTP Server.
Releases
Packages
- 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 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 21.04
Ubuntu 20.10
Ubuntu 20.04
Ubuntu 18.04
In general, a standard system update will make all the necessary changes.