CWE

Use of Wrong Operator in String Comparison

ID: 597		Date: (C)2012-05-14   (M)2022-10-10
Type: weakness		Status: DRAFT
Abstraction Type: Variant

Description

The product uses the wrong operator when comparing a string, such as using "==" when the equals() method should be used instead.

Extended Description

In Java, using == or != to compare two strings for equality actually compares two objects for equality, not their values. Chances are good that the two references will never be equal. While this weakness often only affects program correctness, if the equality is used for a security decision, it could be leveraged to affect program security.

Applicable Platforms
None

Time Of Introduction

• Implementation

Common Consequences

Scope	Technical Impact	Notes
Other	Other

Detection Methods
None

Potential Mitigations

Phase	Strategy	Description	Effectiveness	Notes
Implementation		Use equals() to compare strings.	High

Relationships

Related CWE	Type	View	Chain
CWE-597 ChildOf CWE-885	Category	CWE-888

Demonstrative Examples   (Details)

1. In the example below, two Java String objects are declared and initialized with the same string values and an if statement is used to determine if the strings are equivalent. (Demonstrative Example Id DX-60)

White Box Definitions
None

Black Box Definitions
None

Taxynomy Mappings

Taxynomy	Id	Name	Fit
CERT Java Secure Coding	EXP03-J	Do not use the equality operators when comparing values of boxed primitives
CERT Java Secure Coding	EXP03-J	Do not use the equality operators when comparing values of boxed primitives

References:

1. Mark Dowd John McDonald Justin Schuh .The Art of Software Security Assessment 1st Edition. Addison Wesley. Section:'Chapter 6, "Typos", Page 289.'. Published on 2006.