CWE-581 Detail

CWE-581

Object Model Violation: Just One of Equals and Hashcode Defined
Draft
2006-12-15
00h00 +00:00
2024-02-29
00h00 +00:00
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Name: Object Model Violation: Just One of Equals and Hashcode Defined

The product does not maintain equal hashcodes for equal objects.

CWE Description

Java objects are expected to obey a number of invariants related to equality. One of these invariants is that equal objects must have equal hashcodes. In other words, if a.equals(b) == true then a.hashCode() == b.hashCode().

General Informations

Modes Of Introduction

Implementation

Applicable Platforms

Language

Name: Java (Undetermined)

Common Consequences

Scope Impact Likelihood
Integrity
Other		Other

Note: If this invariant is not upheld, it is likely to cause trouble if objects of this class are stored in a collection. If the objects of the class in question are used as a key in a Hashtable or if they are inserted into a Map or Set, it is critical that equal objects have equal hashcodes.

Potential Mitigations

Phases : Implementation
Both Equals() and Hashcode() should be defined.

Detection Methods

Automated Static Analysis

Automated static analysis, commonly referred to as Static Application Security Testing (SAST), can find some instances of this weakness by analyzing source code (or binary/compiled code) without having to execute it. Typically, this is done by building a model of data flow and control flow, then searching for potentially-vulnerable patterns that connect "sources" (origins of input) with "sinks" (destinations where the data interacts with external components, a lower layer such as the OS, etc.)
Effectiveness : High

Vulnerability Mapping Notes

Justification : This CWE entry is at the Base level of abstraction, which is a preferred level of abstraction for mapping to the root causes of vulnerabilities.
Comment : Carefully read both the name and description to ensure that this mapping is an appropriate fit. Do not try to 'force' a mapping to a lower-level Base/Variant simply to comply with this preferred level of abstraction.

Submission

Name Organization Date Date release Version
CWE Community 2006-12-15 +00:00 2006-12-15 +00:00 Draft 5

Modifications

Name Organization Date Comment
Eric Dalci Cigital 2008-07-01 +00:00 updated Potential_Mitigations, Time_of_Introduction
CWE Content Team MITRE 2008-09-08 +00:00 updated Common_Consequences, Relationships, Other_Notes
CWE Content Team MITRE 2009-10-29 +00:00 updated Common_Consequences, Description, Other_Notes
CWE Content Team MITRE 2010-12-13 +00:00 updated Common_Consequences
CWE Content Team MITRE 2011-03-29 +00:00 updated Description
CWE Content Team MITRE 2011-06-01 +00:00 updated Common_Consequences, Relationships, Taxonomy_Mappings
CWE Content Team MITRE 2012-05-11 +00:00 updated Relationships, Taxonomy_Mappings
CWE Content Team MITRE 2012-10-30 +00:00 updated Potential_Mitigations
CWE Content Team MITRE 2014-07-30 +00:00 updated Relationships
CWE Content Team MITRE 2018-03-27 +00:00 updated Relationships
CWE Content Team MITRE 2019-01-03 +00:00 updated Relationships, Taxonomy_Mappings
CWE Content Team MITRE 2020-02-24 +00:00 updated Relationships
CWE Content Team MITRE 2023-01-31 +00:00 updated Description
CWE Content Team MITRE 2023-04-27 +00:00 updated Detection_Factors, Relationships
CWE Content Team MITRE 2023-06-29 +00:00 updated Mapping_Notes
CWE Content Team MITRE 2024-02-29 +00:00 updated Type