USN-5090-3: Apache HTTP Server regression

28 September 2021

USN-5090-1 introduced a regression in Apache HTTP Server.

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Details

USN-5090-1 fixed vulnerabilities in Apache HTTP Server. One of the upstream
fixes introduced a regression in UDS URIs. This update fixes the problem.

Original advisory details:

James Kettle discovered that the Apache HTTP Server HTTP/2 module
incorrectly handled certain crafted methods. A remote attacker could
possibly use this issue to perform request splitting or cache poisoning
attacks. (CVE-2021-33193)

It was discovered that the Apache HTTP Server incorrectly handled certain
malformed requests. A remote attacker could possibly use this issue to
cause the server to crash, resulting in a denial of service.
(CVE-2021-34798)

Li Zhi Xin discovered that the Apache mod_proxy_uwsgi module incorrectly
handled certain request uri-paths. A remote attacker could possibly use
this issue to cause the server to crash, resulting in a denial of service.
This issue only affected Ubuntu 20.04 LTS and Ubuntu 21.04.
(CVE-2021-36160)

It was discovered that the Apache HTTP Server incorrectly handled escaping
quotes. If the server was configured with third-party modules, 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-2021-39275)

It was discovered that the Apache mod_proxy module incorrectly handled
certain request uri-paths. A remote attacker could possibly use this issue
to cause the server to forward requests to arbitrary origin servers.
(CVE-2021-40438)

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Ubuntu Pro provides ten-year security coverage to 25,000+ packages in Main and Universe repositories, and it is free for up to five machines.

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Update instructions

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

Ubuntu 21.04
Ubuntu 20.04
Ubuntu 18.04

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