A Lasso security update has been released for Ubuntu Linux 18.04 LTS, 20.04 LTS, 20.10, and 21.04.

USN-4974-1: Lasso vulnerability

=========================================================================
Ubuntu Security Notice USN-4974-1
June 02, 2021

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

- Ubuntu 21.04
- Ubuntu 20.10
- Ubuntu 20.04 LTS
- Ubuntu 18.04 LTS

Summary:

Applications using Lasso could be made to allow unintended access.

Software Description:
- lasso: Liberty Alliance and SAML protocol Library

Details:

It was discovered that Lasso did not properly verify that all
assertions in a SAML response were properly signed. An attacker
could possibly use this to impersonate users or otherwise bypass
access controls.

Update instructions:

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

Ubuntu 21.04:
liblasso-perl 2.6.1-2ubuntu0.1
liblasso3 2.6.1-2ubuntu0.1
python3-lasso 2.6.1-2ubuntu0.1

Ubuntu 20.10:
liblasso-perl 2.6.0-7ubuntu2.1
liblasso3 2.6.0-7ubuntu2.1
python3-lasso 2.6.0-7ubuntu2.1

Ubuntu 20.04 LTS:
liblasso-perl 2.6.0-7ubuntu1.2
liblasso3 2.6.0-7ubuntu1.2
python3-lasso 2.6.0-7ubuntu1.2

Ubuntu 18.04 LTS:
liblasso-perl 2.5.1-0ubuntu1.2
liblasso3 2.5.1-0ubuntu1.2
python-lasso 2.5.1-0ubuntu1.2
python3-lasso 2.5.1-0ubuntu1.2

After a standard system update you need to restart applications that use
Lasso to make all the necessary changes.

References:
  https://ubuntu.com/security/notices/USN-4974-1
CVE-2021-28091

Package Information:
  https://launchpad.net/ubuntu/+source/lasso/2.6.1-2ubuntu0.1
  https://launchpad.net/ubuntu/+source/lasso/2.6.0-7ubuntu2.1
  https://launchpad.net/ubuntu/+source/lasso/2.6.0-7ubuntu1.2
  https://launchpad.net/ubuntu/+source/lasso/2.5.1-0ubuntu1.2