USN-4245-1: PySAML2 vulnerability

21 January 2020

python-pysaml2 vulnerability

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

  • Ubuntu 19.10
  • Ubuntu 19.04
  • Ubuntu 18.04 LTS
  • Ubuntu 16.04 LTS


PySAML2 could be made to bypass signature verification with arbitrary data.

Software Description

  • python-pysaml2 - Pure python implementation of SAML2


It was discovered that PySAML2 incorrectly handled certain SAML files. An attacker could possibly use this issue to bypass signature verification with arbitrary data.

Update instructions

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

Ubuntu 19.10
python-pysaml2 - 4.5.0+dfsg1-0ubuntu2.19.10.1
python3-pysaml2 - 4.5.0+dfsg1-0ubuntu2.19.10.1
Ubuntu 19.04
python-pysaml2 - 4.5.0+dfsg1-0ubuntu2.19.04.1
python3-pysaml2 - 4.5.0+dfsg1-0ubuntu2.19.04.1
Ubuntu 18.04 LTS
python-pysaml2 - 4.0.2-0ubuntu3.1
python3-pysaml2 - 4.0.2-0ubuntu3.1
Ubuntu 16.04 LTS
python-pysaml2 - 3.0.0-3ubuntu1.16.04.4
python3-pysaml2 - 3.0.0-3ubuntu1.16.04.4

To update your system, please follow these instructions:

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