1. Ubuntu Security Notices
  2. USN-4940-1

USN-4940-1: PyYAML vulnerability

Publication date

10 May 2021

Overview

PyYAML could be made to run programs if it opened a specially crafted YAML file.

Releases

Packages

  • pyyaml - YAML parser and emitter for Python

Details

It was discovered that PyYAML incorrectly handled untrusted YAML files with
the FullLoader loader. A remote attacker could possibly use this issue to
execute arbitrary code.

It was discovered that PyYAML incorrectly handled untrusted YAML files with
the FullLoader loader. A remote attacker could possibly use this issue to
execute arbitrary code.

Update instructions

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

Learn more about how to get the fixes.

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

Ubuntu Release Package Version
20.10 groovy python3-yaml –  5.3.1-2ubuntu0.1
20.04 focal python-yaml –  5.3.1-1ubuntu0.1
python3-yaml –  5.3.1-1ubuntu0.1

Reduce your security exposure

Ubuntu Pro provides ten-year security coverage to 25,000+ packages in Main and Universe repositories, and it is free for up to five machines.

Get Ubuntu Pro

References

Have additional questions?

Talk to a member of the team ›