A Python 2.7 security update has been released for Ubuntu Linux 16.04 LTS and 18.04 LTS.

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Ubuntu Security Notice USN-4754-4
March 03, 2021

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

- Ubuntu 18.04 LTS
- Ubuntu 16.04 LTS

Summary:

Python could be made to execute arbitrary code or denial of service if it
received a specially crafted input.

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

Details:

USN-4754-1 fixed vulnerabilities in Python. Because of a regression, a
subsequent update removed the fix for CVE-2021-3177. This update reinstates
the security fix for CVE-2021-3177.

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 2.7.17-1~18.04ubuntu1.6
python2.7-minimal 2.7.17-1~18.04ubuntu1.6

Ubuntu 16.04 LTS:
python2.7 2.7.12-1ubuntu0~16.04.18
python2.7-minimal 2.7.12-1ubuntu0~16.04.18

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

References:
  https://usn.ubuntu.com/4754-4
  https://usn.ubuntu.com/4754-1
CVE-2021-3177

Package Information:
  https://launchpad.net/ubuntu/+source/python2.7/2.7.17-1~18.04ubuntu1.6
  https://launchpad.net/ubuntu/+source/python2.7/2.7.12-1ubuntu0~16.04.18