Debian: DSA-4350-1 Severe: Policykit Authentication Bypass Issue

It was discovered that incorrect processing of very high UIDs in
Policykit, a framework for managing administrative policies and
privileges, could result in authentication bypass.

For the stable distribution (stretch), this problem has been fixed in
version 0.105-18+deb9u1.

We recommend that you upgrade your policykit-1 packages.

For the detailed security status of policykit-1 please refer to
its security tracker page at:
https://security-tracker.debian.org/tracker/source-package/policykit-1

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/