A mod-auth-mellon security update has been released for Ubuntu Linux 21.04.

==========================================================================
Ubuntu Security Notice USN-5069-2
September 08, 2021

libapache2-mod-auth-mellon vulnerability
==========================================================================

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

- Ubuntu 21.04

Summary:

mod-auth-mellon could be made to redirect to arbitrary sites.

Software Description:
- libapache2-mod-auth-mellon: SAML 2.0 authentication module for Apache

Details:

USN-5069-1 fixed a vulnerability in mod-auth-mellon. This update provides
the corresponding updates for Ubuntu 21.04.

Original advisory details:

It was discovered that mod-auth-mellon incorrectly filtered certain URLs.
A remote attacker could possibly use this issue to perform an open redirect
attack.

Update instructions:

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

Ubuntu 21.04:
libapache2-mod-auth-mellon 0.17.0-1ubuntu0.21.04.1

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

References:
  https://ubuntu.com/security/notices/USN-5069-2
  https://ubuntu.com/security/notices/USN-5069-1
CVE-2021-3639

Package Information:

  https://launchpad.net/ubuntu/+source/libapache2-mod-auth-mellon/0.17.0-1ubuntu0.21.04.1