A nginx security update has been released for Ubuntu Linux 16.04 ESM, 18.04 LTS, 20.04 LTS, and 21.10.

==========================================================================
Ubuntu Security Notice USN-5371-1
April 13, 2022

nginx vulnerabilities
==========================================================================

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

- Ubuntu 21.10
- Ubuntu 20.04 LTS
- Ubuntu 18.04 LTS
- Ubuntu 16.04 ESM

Summary:

Several security issues were fixed in nginx.

Software Description:
- nginx: small, powerful, scalable web/proxy server

Details:

It was discovered that nginx Lua module mishandled certain inputs.
An attacker could possibly use this issue to perform an HTTP Request
Smuggling attack. This issue only affects Ubuntu 18.04 LTS and
Ubuntu 20.04 LTS. (CVE-2020-11724)

It was discovered that nginx Lua module mishandled certain inputs.
An attacker could possibly use this issue to disclose sensitive
information. This issue only affects Ubuntu 18.04 LTS and
Ubuntu 20.04 LTS. (CVE-2020-36309)

It was discovered that nginx mishandled the use of
compatible certificates among multiple encryption protocols.
If a remote attacker were able to intercept the communication,
this issue could be used to redirect traffic between subdomains.
(CVE-2021-3618)

Update instructions:

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

Ubuntu 21.10:
nginx-core 1.18.0-6ubuntu11.1
nginx-extras 1.18.0-6ubuntu11.1
nginx-light 1.18.0-6ubuntu11.1

Ubuntu 20.04 LTS:
libnginx-mod-http-lua 1.18.0-0ubuntu1.3
nginx-core 1.18.0-0ubuntu1.3
nginx-extras 1.18.0-0ubuntu1.3
nginx-full 1.18.0-0ubuntu1.3
nginx-light 1.18.0-0ubuntu1.3

Ubuntu 18.04 LTS:
libnginx-mod-http-lua 1.14.0-0ubuntu1.10
nginx-core 1.14.0-0ubuntu1.10
nginx-extras 1.14.0-0ubuntu1.10
nginx-full 1.14.0-0ubuntu1.10
nginx-light 1.14.0-0ubuntu1.10

Ubuntu 16.04 ESM:
nginx-core 1.10.3-0ubuntu0.16.04.5+esm3
nginx-extras 1.10.3-0ubuntu0.16.04.5+esm3
nginx-light 1.10.3-0ubuntu0.16.04.5+esm3

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

References:
https://ubuntu.com/security/notices/USN-5371-1
CVE-2020-11724, CVE-2020-36309, CVE-2021-3618

Package Information:
https://launchpad.net/ubuntu/+source/nginx/1.18.0-6ubuntu11.1
https://launchpad.net/ubuntu/+source/nginx/1.18.0-0ubuntu1.3
https://launchpad.net/ubuntu/+source/nginx/1.14.0-0ubuntu1.10