Encoding Error
Weakness ID: 172 (Weakness Class)Status: Draft
+ Description

Description Summary

The software fails to properly handle encoding or decoding of the data, resulting in unexpected values.
+ Time of Introduction
  • Implementation
+ Applicable Platforms



+ Potential Mitigations

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)
ChildOfCategoryCategory171Cleansing, Canonicalization, and Comparison Errors
Development Concepts (primary)699
ChildOfWeakness ClassWeakness Class707Improper Enforcement of Message or Data Structure
Research Concepts (primary)1000
CanPrecedeWeakness ClassWeakness Class22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
Research Concepts1000
CanPrecedeWeakness BaseWeakness Base41Improper Resolution of Path Equivalence
Research Concepts1000
ParentOfWeakness VariantWeakness Variant173Failure to Handle Alternate Encoding
Development Concepts (primary)699
Research Concepts (primary)1000
ParentOfWeakness VariantWeakness Variant174Double Decoding of the Same Data
Development Concepts (primary)699
Research Concepts1000
ParentOfWeakness VariantWeakness Variant175Failure to Handle Mixed Encoding
Development Concepts (primary)699
Research Concepts (primary)1000
ParentOfWeakness VariantWeakness Variant176Failure to Handle Unicode Encoding
Development Concepts (primary)699
Research Concepts (primary)1000
ParentOfWeakness VariantWeakness Variant177Failure to Handle URL Encoding (Hex Encoding)
Development Concepts (primary)699
Research Concepts (primary)1000
+ Relationship Notes

Partially overlaps path traversal and equivalence weaknesses.

+ Taxonomy Mappings
Mapped Taxonomy NameNode IDFitMapped Node Name
PLOVEREncoding Error
+ Related Attack Patterns
CAPEC-IDAttack Pattern Name
(CAPEC Version: 1.4)
3Using Leading 'Ghost' Character Sequences to Bypass Input Filters
52Embedding NULL Bytes
53Postfix, Null Terminate, and Backslash
64Using Slashes and URL Encoding Combined to Bypass Validation Logic
72URL Encoding
78Using Escaped Slashes in Alternate Encoding
71Using Unicode Encoding to Bypass Validation Logic
80Using UTF-8 Encoding to Bypass Validation Logic
+ Maintenance Notes

This is more like a category than a weakness.

Many other types of encodings should be listed in this category.

+ Content History
Submission DateSubmitterOrganizationSource
PLOVERExternally Mined
Modification DateModifierOrganizationSource
2008-07-01Eric DalciCigitalExternal
updated Potential Mitigations, Time of Introduction
2008-09-08CWE Content TeamMITREInternal
updated Maintenance Notes, Relationships, Relationship Notes, Taxonomy Mappings
2009-07-27CWE Content TeamMITREInternal
updated Potential Mitigations