Debian: DSA-4716-1 Moderate: Docker.io IPv6 Router Spoofing Fix

Etienne Champetier discovered that Docker, a Linux container runtime,
created network bridges which by default accept IPv6 router advertisements.
This could allow an attacker with the CAP_NET_RAW capability in a
container to spoof router advertisements, resulting in information
disclosure or denial of service.

For the stable distribution (buster), this problem has been fixed in
version 18.09.1+dfsg1-7.1+deb10u2.

We recommend that you upgrade your docker.io packages.

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

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/