Memory leak in wpanctl can lead to DoS

A memory leak in Openthread's wpantund versions up to commit 0e5d1601febb869f583e944785e5685c6c747be7, when used in an environment where wpanctl is directly interfacing with the control driver (eg: debug environments) can allow an attacker to crash the service (DoS). We recommend updating, or to restrict access in your debug environments.