CWE-395: Use of NullPointerException Catch to Detect NULL Pointer Dereference
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
Languages
Java
Common Consequences
Scope
Effect
Availability
Technical Impact: DoS: resource consumption
(CPU)
Demonstrative Examples
Example 1
The following code mistakenly catches a
NullPointerException.
(Bad Code)
Example
Language: Java
try {
mysteryMethod();
} 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:
The program contains a null pointer dereference. Catching the
resulting exception was easier than fixing the underlying
problem.
The program explicitly throws a NullPointerException to signal an
error condition.
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.
Description
