ThrottleStop.sys, a legitimate driver, exposes two IOCTL interfaces that allow arbitrary read and write access to physical memory via the MmMapIoSpace function. This insecure implementation can be exploited by a malicious user-mode application to patch the running Windows kernel and invoke arbitrary kernel functions with ring-0 privileges. The vulnerability enables local attackers to execute arbitrary code in kernel context, resulting in privilege escalation and potential follow-on attacks, such as disabling security software or bypassing kernel-level protections. ThrottleStop.sys version 3.0.0.0 and possibly others are affected. Apply updates per vendor instructions.
The product implements an IOCTL with functionality that should be restricted, but it does not properly enforce access control for the IOCTL.
When an IOCTL contains privileged functionality and is exposed unnecessarily, attackers may be able to access this functionality by invoking the IOCTL. Even if the functionality is benign, if the programmer has assumed that the IOCTL would only be accessed by a trusted process, there may be little or no validation of the incoming data, exposing weaknesses that would never be reachable if the attacker cannot call the IOCTL directly. The implementations of IOCTLs will differ between operating system types and versions, so the methods of attack and prevention may vary widely.