This vulnerability allows local attackers to escalate privileges on vulnerable installations of Joyent SmartOS release-20170803-20170803T064301Z. An attacker must first obtain the ability to execute low-privileged code on the target system in order to exploit this vulnerability. The specific flaw exists within the SMBIOC_TREE_RELE ioctl. The issue results from the lack of validating the existence of an object prior to performing operations on the object. An attacker can leverage this vulnerability to execute code under the context of the host OS. Was ZDI-CAN-4984.