CWE

CWE-581 – Object Model Violation: Just One of Equals and Hashcode Defined

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Description

The software does not maintain equal hashcodes for equal objects.

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().

Modes of Introduction:

– Implementation

 

 

Related Weaknesses

CWE-573
CWE-697

 

Consequences

Integrity, Other: Other

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

Phase: Implementation

Description: 

Both Equals() and Hashcode() should be defined.

CVE References

In,

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