Debian: DSA-4971-1 Critical: Postorius Authentication Flaw

Kevin Israel discovered that Postorius, the administrative web frontend
for Mailman 3, didn't validate whether a logged-in user owns the email
address when unsubscribing.

For the oldstable distribution (buster), this problem has been fixed
in version 1.2.4-1+deb10u1.

For the stable distribution (bullseye), this problem has been fixed in
version 1.3.4-2+deb11u1.

We recommend that you upgrade your postorius packages.

For the detailed security status of postorius please refer to
its security tracker page at:
https://security-tracker.debian.org/tracker/source-package/postorius

Further information about Debian Security Advisories, how to apply
these updates to your system and frequently asked questions can be
found at: https://www.debian.org/security/