CWE 781

Phase: Implementation

If METHOD_NEITHER is required for the IOCTL, then ensure that all user-space addresses are properly validated before they are first accessed. The ProbeForRead and ProbeForWrite routines are available for this task. Also properly protect and manage the user-supplied buffers, since the I/O Manager does not do this when METHOD_NEITHER is being used. See References.

Phase: Architecture and Design

If possible, avoid using METHOD_NEITHER in the IOCTL and select methods that effectively control the buffer size, such as METHOD_BUFFERED, METHOD_IN_DIRECT, or METHOD_OUT_DIRECT.

Phases: Architecture and Design; Implementation

If the IOCTL is part of a driver that is only intended to be accessed by trusted users, then use proper access control for the associated device or device namespace. See References.

While this type of issue has been known since 2006, it is probably still under-studied and under-reported. Most of the focus has been on high-profile software and security products, but other kinds of system software also use drivers. Since exploitation requires the development of custom code, it requires some skill to find this weakness.

Because exploitation typically requires local privileges, it might not be a priority for active attackers. However, remote exploitation may be possible for software such as device drivers. Even when remote vectors are not available, it may be useful as the final privilege-escalation step in multi-stage remote attacks against application-layer software, or as the primary attack by a local user on a multi-user system.