A vulnerability exists in the latest version of Razer Synapse
(v126.96.36.1994 as of the day of disclosure) which can be leveraged
locally by a malicious application to elevate its privileges to those of
NT_AUTHORITY\SYSTEM. The vulnerability lies in a specific IOCTL handler
in the rzpnk.sys driver that passes a PID specified by the user to
ZwOpenProcess. This can be issued by an application to open a handle to
an arbitrary process with the necessary privileges to allocate, read and
write memory in the specified process.
This exploit leverages this vulnerability to open a handle to the
winlogon process (which runs as NT_AUTHORITY\SYSTEM) and infect it by
installing a hook to execute attacker controlled shellcode. This hook is
then triggered on demand by calling user32!LockWorkStation(), resulting
in the attacker's payload being executed with the privileges of the
infected winlogon process. In order for the issued IOCTL to work, the
RazerIngameEngine.exe process must not be running. This exploit will
check if it is, and attempt to kill it as necessary.
The vulnerable software can be found here:
https://www.razerzone.com/synapse/. No Razer hardware needs to be
connected in order to leverage this vulnerability.
This exploit is not opsec-safe due to the user being logged out as part
of the exploitation process.