CWE

Common Weakness Enumeration

A Community-Developed List of Software Weakness Types

CWE/SANS Top 25 Most Dangerous Software Errors
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ID

CWE-596: Incorrect Semantic Object Comparison

Weakness ID: 596
Abstraction: Base
Status: Incomplete
Presentation Filter:
+ Description

Description Summary

The software does not correctly compare two objects based on their conceptual content.
+ Time of Introduction
  • Implementation
+ Common Consequences
ScopeEffect
Other

Technical Impact: Other

+ Detection Methods

Manual Static Analysis

Requires domain-specific knowledge to determine if the comparison is incorrect.

+ Demonstrative Examples

Example 1

For example, let's say you have two truck objects that you want to compare for equality. Truck objects are defined to be the same if they have the same make, the same model, and were manufactured in the same year. A Semantic Incorrect Object Comparison would occur if only two of the three factors were checked for equality. So if only make and model are compared and the year is ignored, then you have an incorrect object comparison.

(Bad Code)
Example Language: Java 
public class Truck {
private String make;
private String model;
private int year;

public boolean equals(Object o) {
if (o == null) return false;
if (o == this) return true;
if (!(o instanceof Truck)) return false;

Truck t = (Truck) o;

return (this.make.equals(t.getMake()) && this.model.equals(t.getModel()));
}
}
+ Relationships
NatureTypeIDNameView(s) this relationship pertains toView(s)
ChildOfCategoryCategory171Cleansing, Canonicalization, and Comparison Errors
Development Concepts699
ChildOfCategoryCategory569Expression Issues
Development Concepts (primary)699
ChildOfWeakness ClassWeakness Class697Insufficient Comparison
Research Concepts (primary)1000
ChildOfCategoryCategory840Business Logic Errors
Development Concepts699
ChildOfCategoryCategory977SFP Secondary Cluster: Design
Software Fault Pattern (SFP) Clusters (primary)888
+ Content History
Modifications
Modification DateModifierOrganizationSource
2008-07-01Sean EidemillerCigitalExternal
added/updated demonstrative examples
2008-07-01Eric DalciCigitalExternal
updated Time_of_Introduction
2008-09-08CWE Content TeamMITREInternal
updated Description, Detection_Factors, Relationships
2010-02-16CWE Content TeamMITREInternal
updated Detection_Factors
2011-03-29CWE Content TeamMITREInternal
updated Relationships
2011-06-01CWE Content TeamMITREInternal
updated Common_Consequences
2012-05-11CWE Content TeamMITREInternal
updated Relationships
2014-07-30CWE Content TeamMITREInternal
updated Relationships
Previous Entry Names
Change DatePrevious Entry Name
2008-04-11Incorrect Object Comparison: Semantic

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Page Last Updated: May 05, 2017