Improper Handling of Missing Special Element
Weakness ID: 166 (Weakness Base)Status: Draft
+ Description

Description Summary

The software receives input from an upstream component, but it does not handle or incorrectly handles when an expected special element is missing.
+ Time of Introduction
  • Implementation
+ Applicable Platforms

Languages

All

+ Observed Examples
ReferenceDescription
CVE-2002-1362Crash via message type without separator character
CVE-2002-0729Missing special character (separator) causes crash
CVE-2002-1532HTTP GET without \r\n\r\n CRLF sequences causes product to wait indefinitely and prevents other users from accessing it
+ Potential Mitigations

Developers should anticipate that special elements will be removed in the input vectors of their software system. Use an appropriate combination of black lists and white lists to ensure only valid, expected and appropriate input is processed by the system.

Phase: Architecture and Design

Assume all input is malicious. Use a standard input validation mechanism to validate all input for length, type, syntax, and business rules before accepting the data to be displayed or stored. Use an "accept known good" validation strategy.

Use and specify a strong output encoding (such as ISO 8859-1 or UTF 8).

Do not rely exclusively on blacklist validation to detect malicious input or to encode output. There are too many variants to encode a character; you're likely to miss some variants.

Inputs should be decoded and canonicalized to the application's current internal representation before being validated. Make sure that your application does not decode the same input twice. Such errors could be used to bypass whitelist schemes by introducing dangerous inputs after they have been checked.

+ Relationships
NatureTypeIDNameView(s) this relationship pertains toView(s)
ChildOfWeakness ClassWeakness Class159Failure to Sanitize Special Element
Development Concepts (primary)699
Research Concepts (primary)1000
ChildOfWeakness ClassWeakness Class703Failure to Handle Exceptional Conditions
Research Concepts1000
ChildOfCategoryCategory722OWASP Top Ten 2004 Category A1 - Unvalidated Input
Weaknesses in OWASP Top Ten (2004) (primary)711
+ Taxonomy Mappings
Mapped Taxonomy NameNode IDFitMapped Node Name
PLOVERMissing Special Element
+ Content History
Submissions
Submission DateSubmitterOrganizationSource
PLOVERExternally Mined
Modifications
Modification DateModifierOrganizationSource
2008-07-01Eric DalciCigitalExternal
updated Potential Mitigations, Time of Introduction
2008-09-08CWE Content TeamMITREInternal
updated Relationships, Other Notes, Taxonomy Mappings
2009-03-10CWE Content TeamMITREInternal
updated Relationships
2009-05-27CWE Content TeamMITREInternal
updated Description, Name
2009-07-27CWE Content TeamMITREInternal
updated Potential Mitigations
2009-10-29CWE Content TeamMITREInternal
updated Other Notes
Previous Entry Names
Change DatePrevious Entry Name
2008-04-11Missing Special Element
2009-05-27Failure to Handle Missing Special Element