Debian: DSA-3862-1 Urgent: YAML Deserialization Threat in Puppet

It was discovered that unrestricted YAML deserialisation of data sent
from agents to the server in the Puppet configuration management system
could result in the execution of arbitrary code.

Note that this fix breaks backward compability with Puppet agents older
than 3.2.2 and there is no safe way to restore it. This affects puppet
agents running on Debian wheezy; we recommend to update the the
puppet version shipped in wheezy-backports.

For the stable distribution (jessie), this problem has been fixed in
version 3.7.2-4+deb8u1.

For the unstable distribution (sid), this problem has been fixed in
version 4.8.2-5.

We recommend that you upgrade your puppet packages.

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/