The 2016 Pwnie Nominee For Best Privilege Escalation Bug

Apple Mac OS X WindowServer Use-After-Free (CVE-2016-1804)

Credit: Keen Security Lab of Tencent

From the advisory:

This vulnerability allows local attackers to execute arbitrary code on vulnerable installations of Apple OS X. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file. The specific flaw exists within the handling of CFData objects within the WindowServer process. An attacker can cause a CFData object in memory to be reused after it has been freed. An attacker can leverage this vulnerability to execute arbitrary code under the context of the WindowServer.

Apple Mac OS X WindowServer Use-After-FreeĀ 

(CVE-2016-1804)