Function Call With Incorrect Number of Arguments

Draft Variant
Structure: Simple
Description

This weakness occurs when a program calls a function, method, or subroutine but provides the wrong number of arguments—either too many or too few. This mismatch can cause the program to behave unpredictably, access incorrect memory, or crash, creating a security vulnerability.

Extended Description

When a function is called with an incorrect argument count, the underlying system mechanics break down. The calling code and the function have mismatched expectations about how data is arranged on the stack or in registers. This can lead to the function reading invalid values, interpreting data incorrectly (like treating a string as a pointer), or corrupting adjacent memory. The immediate result is often undefined behavior, which can manifest as crashes, data corruption, or unexpected program flow. From a security perspective, this flaw is a gateway for more severe exploits. An attacker might manipulate this mismatch to leak sensitive data from memory, bypass security checks, or execute arbitrary code. It's commonly seen in languages that don't enforce strict type checking at compile-time (like C or C++), in cases of incorrect function pointer usage, or when interfacing with external libraries. Developers must ensure function signatures are always correctly matched, especially when using dynamic linking or callback mechanisms.

Common Consequences 1
Scope: Other

Impact: Quality Degradation

Detection Methods 1
Other
While this weakness might be caught by the compiler in some languages, it can occur more frequently in cases in which the called function accepts variable numbers of arguments, such as format strings in C. It also can occur in languages or environments that do not require that functions always be called with the correct number of arguments, such as Perl.
Potential Mitigations 1
Phase: Testing
Because this function call often produces incorrect behavior it will usually be detected during testing or normal operation of the product. During testing exercise all possible control paths will typically expose this weakness except in rare cases when the incorrect function call accidentally produces the correct results or if the provided argument type is very similar to the expected argument type.
Applicable Platforms
Languages:
C : UndeterminedPerl : Undetermined
Modes of Introduction
Implementation
Taxonomy Mapping
  • Software Fault Patterns
  • CERT C Secure Coding
  • CERT C Secure Coding