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Ubuntu Security Notice USN-5371-2
April 28, 2022

nginx vulnerability

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

• Ubuntu 22.04 LTS

Summary:

nginx could be made to redirect network traffic.

Software Description:

• nginx: small, powerful, scalable web/proxy server

Details:

USN-5371-1 fixed several vulnerabilities in nginx.
This update provides the fix for CVE-2021-3618 for Ubuntu 22.04 LTS.

Original advisory 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 22.04 LTS:
nginx-core 1.18.0-6ubuntu14.1
nginx-extras 1.18.0-6ubuntu14.1
nginx-light 1.18.0-6ubuntu14.1

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

References:
https://ubuntu.com/security/notices/USN-5371-2
https://ubuntu.com/security/notices/USN-5371-1
CVE-2021-3618

Package Information:
https://launchpad.net/ubuntu/+source/nginx/1.18.0-6ubuntu14.1