Improper Handling of Parameters

Description

This vulnerability occurs when software fails to correctly process input that contains an unexpected number of parameters, missing fields, or undefined arguments. It often leads to crashes, unexpected behavior, or security bypasses.

Extended Description

At its core, this weakness is about poor input validation and error handling. When an application expects a specific set of data—like form fields, API parameters, or function arguments—but receives fewer, more, or undefined values, it must handle this gracefully. Without proper checks, the software might try to access non-existent data, causing errors like null pointer dereferences, out-of-bounds access, or logic flaws that attackers can exploit to crash the system or bypass security controls. To prevent this, developers should implement strict input validation at all entry points. Always define and enforce the expected structure, count, and presence of all parameters. Use safe access patterns, such as checking for a parameter's existence before using it, and provide default values where appropriate. Robust error handling routines should catch and manage malformed requests without exposing sensitive debug information, ensuring the application remains stable and secure even when faced with unexpected input.

Common Consequences 1

Scope: Integrity

Impact: Unexpected State

Detection Methods 2

FuzzingHigh

Fuzz testing (fuzzing) is a powerful technique for generating large numbers of diverse inputs - either randomly or algorithmically - and dynamically invoking the code with those inputs. Even with random inputs, it is often capable of generating unexpected results such as crashes, memory corruption, or resource consumption. Fuzzing effectively produces repeatable test cases that clearly indicate bugs, which helps developers to diagnose the issues.

Automated Static AnalysisHigh

Automated static analysis, commonly referred to as Static Application Security Testing (SAST), can find some instances of this weakness by analyzing source code (or binary/compiled code) without having to execute it. Typically, this is done by building a model of data flow and control flow, then searching for potentially-vulnerable patterns that connect "sources" (origins of input) with "sinks" (destinations where the data interacts with external components, a lower layer such as the OS, etc.)

Demonstrative Examples 1

ID : DX-110

This Android application has registered to handle a URL when sent an intent:

Code Example:

Bad

Java

...* IntentFilter filter = new IntentFilter("com.example.URLHandler.openURL"); MyReceiver receiver = new MyReceiver(); registerReceiver(receiver, filter);

java

java

The application assumes the URL will always be included in the intent. When the URL is not present, the call to getStringExtra() will return null, thus causing a null pointer exception when length() is called.