USN-4127-1: Python vulnerabilities

9 September 2019

python2.7, python3.5, python3.6, python3.7 vulnerabilities

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

  • Ubuntu 19.04
  • Ubuntu 18.04 LTS
  • Ubuntu 16.04 LTS

Summary

Several security issues were fixed in Python.

Software Description

  • python2.7 - An interactive high-level object-oriented language
  • python3.7 - An interactive high-level object-oriented language
  • python3.6 - An interactive high-level object-oriented language
  • python3.5 - An interactive high-level object-oriented language

Details

It was discovered that Python incorrectly handled certain pickle files. An attacker could possibly use this issue to consume memory, leading to a denial of service. This issue only affected Ubuntu 16.04 LTS and Ubuntu 18.04 LTS. (CVE-2018-20406)

It was discovered that Python incorrectly validated the domain when handling cookies. An attacker could possibly trick Python into sending cookies to the wrong domain. (CVE-2018-20852)

Jonathan Birch and Panayiotis Panayiotou discovered that Python incorrectly handled Unicode encoding during NFKC normalization. An attacker could possibly use this issue to obtain sensitive information. (CVE-2019-9636, CVE-2019-10160)

Colin Read and Nicolas Edet discovered that Python incorrectly handled parsing certain X509 certificates. An attacker could possibly use this issue to cause Python to crash, resulting in a denial of service. This issue only affected Ubuntu 16.04 LTS and Ubuntu 18.04 LTS. (CVE-2019-5010)

It was discovered that Python incorrectly handled certain urls. A remote attacker could possibly use this issue to perform CRLF injection attacks. (CVE-2019-9740, CVE-2019-9947)

Sihoon Lee discovered that Python incorrectly handled the local_file: scheme. A remote attacker could possibly use this issue to bypass blacklist meschanisms. (CVE-2019-9948)

Update instructions

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

Ubuntu 19.04
python2.7 - 2.7.16-2ubuntu0.1
python2.7-minimal - 2.7.16-2ubuntu0.1
python3.7 - 3.7.3-2ubuntu0.1
python3.7-minimal - 3.7.3-2ubuntu0.1
Ubuntu 18.04 LTS
python2.7 - 2.7.15-4ubuntu4~18.04.1
python2.7-minimal - 2.7.15-4ubuntu4~18.04.1
python3.6 - 3.6.8-1~18.04.2
python3.6-minimal - 3.6.8-1~18.04.2
Ubuntu 16.04 LTS
python2.7 - 2.7.12-1ubuntu0~16.04.8
python2.7-minimal - 2.7.12-1ubuntu0~16.04.8
python3.5 - 3.5.2-2ubuntu0~16.04.8
python3.5-minimal - 3.5.2-2ubuntu0~16.04.8

To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.

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

References