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CWE-597 — Use of Wrong Operator in String Comparison

provenance: imported · CWE: CWE-597

CWE-597: Use of Wrong Operator in String Comparison

MITRE CWE weakness

Kind Weakness
Abstraction Variant
Status Draft
Likelihood of exploit

Description

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

In Java, using == or != to compare two strings for equality actually compares two objects for equality rather than their string values for equality. 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, the unintended comparison result could be leveraged to affect program security.

Common consequences

  • Other: Other

Mitigations

Implementation — Within Java, use .equals() to compare string values. Within JavaScript, use == to compare string values. Within PHP, use == to compare a numeric value to a string value. (PHP converts the string to a number.)

References

  • CWE page: https://cwe.mitre.org/data/definitions/597.html
  • CWE list: https://cwe.mitre.org/data/index.html