Catching NullPointerException should not be used as an alternative to programmatic checks to prevent dereferencing a null pointer.
View on MITREProgrammers 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.
Do not extensively rely on catching exceptions (especially for validating user input) to handle errors. Handling exceptions can decrease the performance of an application.
According to SOAR [REF-1479], the following detection techniques may be useful: Highly cost effective: Source code Weakness Analyzer Context-configured Source Code Weakness Analyzer
According to SOAR [REF-1479], the following detection techniques may be useful: Highly cost effective: Formal Methods / Correct-By-Construction Cost effective for partial coverage: Inspection (IEEE 1028 standard) (can apply to requirements, design, source code, etc.)
The following code mistakenly catches a NullPointerException.
No relationship information available for this CWE.
CWE-395: Use of NullPointerException Catch to Detect NULL Pointer Dereference is a Common Weakness Enumeration (CWE) entry maintained by MITRE. Catching NullPointerException should not be used as an alternative to programmatic checks to prevent dereferencing a null pointer. 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.
If exploited, CWE-395 (Use of NullPointerException Catch to Detect NULL Pointer Dereference) it can compromise Availability, leading to outcomes such as DoS: Resource Consumption (CPU).
Recommended mitigations for CWE-395 include: Do not extensively rely on catching exceptions (especially for validating user input) to handle errors. Handling exceptions can decrease the performance of an application.
CWE-395 can be detected using Automated Static Analysis - Source Code and Architecture or Design Review. Combining automated tooling with manual review typically yields the best coverage.
CWE-395 commonly affects Java. Note that weaknesses are often language-agnostic patterns, so secure coding practices apply broadly.
A CWE (Common Weakness Enumeration) like CWE-395 describes a category of software weakness — the underlying flaw type. A CVE (Common Vulnerabilities and Exposures) identifies a specific, real-world vulnerability in a particular product. In short, a CWE is the kind of mistake, and a CVE is an instance of that mistake being found in software.