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CWE-781: Improper Address Validation in IOCTL with METHOD_NEITHER I/O Control Code

Weakness ID: 781
Abstraction: Variant
Status: Draft
Presentation Filter:
+ Description

Description Summary

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.

Extended Description

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
  • Implementation
+ Applicable Platforms


C: (Often)

C++: (Often)

Operating Systems

Windows XP: (Sometimes)

Windows 2000: (Sometimes)

Windows Vista: (Sometimes)

Platform Notes

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.

+ Common Consequences

Technical Impact: Modify memory; Read memory; Execute unauthorized code or commands; DoS: crash / exit / restart

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.

+ Likelihood of Exploit

Low to Medium

+ Observed Examples
Driver for file-sharing and messaging protocol allows attackers to execute arbitrary code.
Anti-virus product does not validate addresses, allowing attackers to gain SYSTEM privileges.
DVD software allows attackers to cause a crash.
Personal firewall allows attackers to gain SYSTEM privileges.
chain: device driver for packet-capturing software allows access to an unintended IOCTL with resultant array index error.
+ Potential Mitigations

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.

+ Relationships
NatureTypeIDNameView(s) this relationship pertains toView(s)
ChildOfWeakness ClassWeakness Class20Improper Input Validation
Development Concepts (primary)699
Research Concepts (primary)1000
ChildOfCategoryCategory465Pointer Issues
Development Concepts699
CanPrecedeWeakness BaseWeakness Base822Untrusted Pointer Dereference
Development Concepts699
CanFollowWeakness VariantWeakness Variant782Exposed IOCTL with Insufficient Access Control
Research Concepts1000
+ Research Gaps

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.

+ References
Ruben Santamarta. "Exploiting Common Flaws in Drivers". 2007-07-11. <>.
Yuriy Bulygin. "Remote and Local Exploitation of Network Drivers". 2007-08-01. <>.
Anibal Sacco. "Windows driver vulnerabilities: the METHOD_NEITHER odyssey". October 2008. <>.
Microsoft. "Buffer Descriptions for I/O Control Codes". <>.
Microsoft. "Using Neither Buffered Nor Direct I/O". <>.
Microsoft. "Securing Device Objects". <>.
+ Content History
Submission DateSubmitterOrganizationSource
2009-07-15MITREInternal CWE Team
Modification DateModifierOrganizationSource
2009-12-28CWE Content TeamMITREInternal
updated Common_Consequences, Potential_Mitigations, References, Time_of_Introduction
2010-09-27CWE Content TeamMITREInternal
updated Relationships
2011-06-01CWE Content TeamMITREInternal
updated Common_Consequences

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Page Last Updated: January 18, 2017