(Pwn2Own) Microsoft Windows CLFS Integer Underflow Local Privilege Escalation Vulnerability

This vulnerability allows local attackers to escalate privileges on affected installations of Microsoft Windows. 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 Common Log File System (CLFS). The issue results from the lack of proper validation of user-supplied data, which can result in an integer underflow before writing to memory. An attacker can leverage this vulnerability to escalate privileges and execute arbitrary code in the context of SYSTEM.