CWE-781: Improper Address Validation in IOCTL with METHOD_NEITHER I/O Control Code
Weakness ID: 781
The software defines an IOCTL that uses METHOD_NEITHER for I/O, but it does not validate or incorrectly validates the addresses that are provided.
When an IOCTL uses the METHOD_NEITHER option for I/O control, it is the responsibility of the IOCTL to validate the addresses that have been supplied to it. If validation is missing or incorrect, attackers can supply arbitrary memory addresses, leading to code execution or a denial of service.
Time of Introduction
Architecture and Design
Windows XP: (Sometimes)
Windows 2000: (Sometimes)
Windows Vista: (Sometimes)
Because IOCTL functionality is typically performing low-level actions and
closely interacts with the operating system, this weakness may only appear
in code that is written in low-level languages.
An attacker may be able to access memory that belongs to another
process or user. If the attacker can control the contents that the IOCTL
writes, it may lead to code execution at high privilege levels. At the
least, a crash can occur.
chain: device driver for packet-capturing software
allows access to an unintended IOCTL with resultant array index
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.