Use of NullPointerException Catch to Detect NULL Pointer Dereference
Weakness ID: 395 (Weakness Base)Status: Draft
+ Description

Description Summary

Catching NullPointerException should not be used as an alternative to programmatic checks to prevent dereferencing a null pointer.
+ Time of Introduction
  • Implementation
+ Applicable Platforms



+ Demonstrative Examples

Example 1

The following code mistakenly catches a NullPointerException.

(Bad Code)
Example Language: Java 
try {
} catch (NullPointerException npe) {

+ Potential Mitigations

Do not extensively rely on catching exceptions (especially for validating user input) to handle errors. Handling exceptions can decrease the performance of an application.

+ Other Notes

Programmers typically catch NullPointerException under three circumstances: 1. The program contains a null pointer dereference. Catching the resulting exception was easier than fixing the underlying problem. 2. The program explicitly throws a NullPointerException to signal an error condition. 3. The code is part of a test harness that supplies unexpected input to the classes under test. Of these three circumstances, only the last is acceptable.

+ Relationships
NatureTypeIDNameView(s) this relationship pertains toView(s)
ChildOfCategoryCategory388Error Handling
Seven Pernicious Kingdoms (primary)700
ChildOfCategoryCategory389Error Conditions, Return Values, Status Codes
Development Concepts (primary)699
ChildOfWeakness ClassWeakness Class691Insufficient Control Flow Management
Research Concepts (primary)1000
ChildOfWeakness ClassWeakness Class755Improper Handling of Exceptional Conditions
Research Concepts1000
+ Taxonomy Mappings
Mapped Taxonomy NameNode IDFitMapped Node Name
7 Pernicious KingdomsCatching NullPointerException
+ Content History
Submission DateSubmitterOrganizationSource
7 Pernicious KingdomsExternally Mined
Modification DateModifierOrganizationSource
2008-07-01Eric DalciCigitalExternal
updated Time of Introduction
2008-09-08CWE Content TeamMITREInternal
updated Relationships, Other Notes, Taxonomy Mappings
2009-03-10CWE Content TeamMITREInternal
updated Relationships
2009-05-27CWE Content TeamMITREInternal
updated Demonstrative Examples
Previous Entry Names
Change DatePrevious Entry Name
2008-04-11Catch NullPointerException