[SECURITY] [DLA 986-1] zookeeper security update

Package : zookeeper
Version : 3.4.5+dfsg-2+deb7u1
CVE ID : CVE-2017-5637
Debian Bug : 863811

It was discovered that Zookeeper, a service for maintaining
configuration information, didn't restrict access to the computationally
expensive wchp/wchc commands which could result in denial of service by
elevated CPU consumption.

This update disables those two commands by default. The new
configuration option "4lw.commands.whitelist" can be used to whitelist
commands selectively (and the full set of commands can be restored
with '*')

For Debian 7 "Wheezy", these problems have been fixed in version
3.4.5+dfsg-2+deb7u1.

We recommend that you upgrade your zookeeper packages.

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