This vulnerability allows local attackers to execute arbitrary code on vulnerable installations of Apple OS X. 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 AppleHSSPIHIDDriver kext. The issue lies in the failure to properly validate the length of user-supplied data prior to copying it to a buffer. An attacker can leverage this vulnerability to escalate privileges under the context of the kernel.