An urllib3 security update has been released for Ubuntu Linux 20.04 LTS, 18.04 LTS, and 16.04 LTS.

USN-4570-1: urllib3 vulnerability

==========================================================================
Ubuntu Security Notice USN-4570-1
October 05, 2020

python-urllib3 vulnerability
==========================================================================

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

- Ubuntu 20.04 LTS
- Ubuntu 18.04 LTS
- Ubuntu 16.04 LTS

Summary:

urllib3 could be used to perform a CRLF injection if it received a
specially crafted request.

Software Description:
- python-urllib3: HTTP library with thread-safe connection pooling

Details:

It was discovered that urllib3 incorrectly handled certain character
sequences. A remote attacker could possibly use this issue to perform CRLF
injection.

Update instructions:

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

Ubuntu 20.04 LTS:
python3-urllib3 1.25.8-2ubuntu0.1

Ubuntu 18.04 LTS:
python-urllib3 1.22-1ubuntu0.18.04.2
python3-urllib3 1.22-1ubuntu0.18.04.2

Ubuntu 16.04 LTS:
python-urllib3 1.13.1-2ubuntu0.16.04.4
python3-urllib3 1.13.1-2ubuntu0.16.04.4

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

References:
  https://usn.ubuntu.com/4570-1
CVE-2020-26137

Package Information:
  https://launchpad.net/ubuntu/+source/python-urllib3/1.25.8-2ubuntu0.1
  https://launchpad.net/ubuntu/+source/python-urllib3/1.22-1ubuntu0.18.04.2
  https://launchpad.net/ubuntu/+source/python-urllib3/1.13.1-2ubuntu0.16.04.4