A Python regression update has been released for Ubuntu Linux 14.04 ESM, 16.04 LTS, and 18.04 LTS.

USN-4754-2: Python regression

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Ubuntu Security Notice USN-4754-2
February 25, 2021

python2.7 regression
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A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 18.04 LTS
- Ubuntu 16.04 LTS
- Ubuntu 14.04 ESM

Summary:

USN-4754-1 introduced a regression in Python2.7.

Software Description:
- python2.7: An interactive high-level object-oriented language

Details:

USN-4754-1 fixed a vulnerability in Python. The fix for CVE-2021-3177 introduced a
regression in Python 2.7. This update reverts the security fix pending further investigation.

We apologize for the inconvenience.

Original advisory details:

It was discovered that Python incorrectly handled certain inputs.
An attacker could possibly use this issue to execute arbitrary code
or cause a denial of service. (CVE-2020-27619, CVE-2021-3177)

Update instructions:

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

Ubuntu 18.04 LTS:
python2.7 2.7.17-1~18.04ubuntu1.5
python2.7-minimal 2.7.17-1~18.04ubuntu1.5

Ubuntu 16.04 LTS:
python2.7 2.7.12-1ubuntu0~16.04.16
python2.7-minimal 2.7.12-1ubuntu0~16.04.16

Ubuntu 14.04 ESM:
python2.7 2.7.6-8ubuntu0.6+esm9
python2.7-minimal 2.7.6-8ubuntu0.6+esm9

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

References:
  https://usn.ubuntu.com/4754-2
  https://usn.ubuntu.com/4754-1
  https://launchpad.net/bugs/1916893

Package Information:
  https://launchpad.net/ubuntu/+source/python2.7/2.7.17-1~18.04ubuntu1.5
  https://launchpad.net/ubuntu/+source/python2.7/2.7.12-1ubuntu0~16.04.16