Improper Handling of Windows Device Names
Weakness ID: 67 (Weakness Variant)Status: Incomplete
+ Description

Description Summary

The software constructs pathnames from user input, but it does not handle or incorrectly handles a pathname containing a Windows device name such as AUX or CON. This typically leads to denial of service or an information leak when the application attempts to process the pathname as a regular file.

Extended Description

Failing to properly handle virtual filenames (e.g. AUX, CON, PRN, COM1, LPT1) can result in different types of vulnerabilities. In some cases an attacker can request a device via injection of a virtual filename in a URL, which may cause an error that leads to a denial of service or an error page that reveals sensitive information. A software system that allows device names to bypass filtering runs the risk of an attacker injecting malicious code in a file with the name of a device.

+ Time of Introduction
  • Architecture and Design
  • Implementation
  • Operation
+ Applicable Platforms



Operating Systems


+ Likelihood of Exploit

High to Very High

+ Potential Mitigations

Be familiar with the device names in the operating system where your system is deployed. Check input for these device names.

+ Background Details

Historically, there was a bug in the Windows operating system that caused a blue screen of death. Even after that issue was fixed DOS device names continue to be a factor.

+ Weakness Ordinalities
(where the weakness is typically related to the presence of some other weaknesses)
+ Relationships
NatureTypeIDNameView(s) this relationship pertains toView(s)
ChildOfWeakness BaseWeakness Base66Improper Handling of File Names that Identify Virtual Resources
Development Concepts (primary)699
Research Concepts (primary)1000
ChildOfCategoryCategory68Windows Virtual File Problems
Resource-specific Weaknesses631
ChildOfCategoryCategory632Weaknesses that Affect Files or Directories
Resource-specific Weaknesses (primary)631
ChildOfCategoryCategory743CERT C Secure Coding Section 09 - Input Output (FIO)
Weaknesses Addressed by the CERT C Secure Coding Standard (primary)734
+ Affected Resources
  • File/Directory
+ Causal Nature


+ Taxonomy Mappings
Mapped Taxonomy NameNode IDFitMapped Node Name
PLOVERWindows MS-DOS device names
CERT C Secure CodingFIO32-CDo not perform operations on devices that are only appropriate for files
+ References
M. Howard and D. LeBlanc. "Writing Secure Code". 2nd Edition. Microsoft. 2003.
+ Content History
Submission DateSubmitterOrganizationSource
PLOVERExternally Mined
Modification DateModifierOrganizationSource
2008-07-01Eric DalciCigitalExternal
updated Time of Introduction
2008-09-08CWE Content TeamMITREInternal
updated Applicable Platforms, Relationships, Other Notes, Taxonomy Mappings, Weakness Ordinalities
2008-10-14CWE Content TeamMITREInternal
updated Description
2008-11-24CWE Content TeamMITREInternal
updated Relationships, Taxonomy Mappings
2009-03-10CWE Content TeamMITREInternal
updated Description, Name
2009-10-29CWE Content TeamMITREInternal
updated Background Details, Other Notes
Previous Entry Names
Change DatePrevious Entry Name
2008-04-11Windows MS-DOS Device Names
2009-03-10Failure to Handle Windows Device Names