The ZooKeeper C client shells "cli_st" and "cli_mt" have a buffer overflow vulnerability associated with parsing of the input command when using the "cmd:<cmd>" batch mode syntax. If the command string exceeds 1024 characters a buffer overflow will occur. There is no known compromise which takes advantage of this vulnerability, and if security is enabled the attacker would be limited by client level security constraints. The C cli shell is intended as a sample/example of how to use the C client interface, not as a production tool - the documentation has also been clarified on this point.

References:

http://seclists.org/bugtraq/2016/Sep/29

Upstream fix:

https://git-wip-us.apache.org/repos/asf?p=zookeeper.git;a=commitdiff;h=27ecf981a15554dc8e64a28630af7a5c9e2bdf4f