What is Function Call With Incorrect Argument (CWE-686)?

TL;DR: Function Call With Incorrect Argument Type (CWE-686) is a vulnerability where an application calls a function with incorrect argument types, leading to potential issues. Fixing it involves ensuring proper type matching and validation.

What is Function Call With Incorrect Argument Type?

Function Call With Incorrect Argument Type (CWE-686) is a type of vulnerability where an application calls a function with incorrect argument types, leading to potential issues. As defined by the MITRE Corporation under CWE-686, and classified by the OWASP Foundation as not directly mapped.

Quick Summary

Function Call With Incorrect Argument Type can lead to unexpected behavior or crashes due to improper handling of parameters. It is crucial for ensuring software reliability and integrity. Jump to: What is Function Call With Incorrect Argument Type? · Overview · How it Works · Business Impact · Attack Scenario · Detection · Fixing · Framework Fixes · AI Prompt · Checklist · FAQ · Related Vulnerabilities

Jump to: Quick Summary · Function Call With Incorrect Argument Type Overview · How Function Call With Incorrect Argument Type Works · Business Impact of Function Call With Incorrect Argument Type · Function Call With Incorrect Argument Type Attack Scenario · How to Detect Function Call With Incorrect Argument Type · How to Fix Function Call With Incorrect Argument Type · Framework-Specific Fixes for Function Call With Incorrect Argument Type · How to Ask AI to Check Your Code for Function Call With Incorrect Argument Type · Function Call With Incorrect Argument Type Best Practices Checklist · Function Call With Incorrect Argument Type FAQ · Vulnerabilities Related to Function Call With Incorrect Argument Type · References · Scan Your Own Site

Function Call With Incorrect Argument Type Overview

What: A vulnerability where a function call specifies an argument with the wrong data type.

Why it matters: Ensuring correct parameter types prevents unexpected behavior and crashes, maintaining application stability.

Where it occurs: Across various programming languages during function calls.

Who is affected: Developers and users of applications that make incorrect function calls.

Who is NOT affected: Systems where functions are called with the correct data type arguments.

How Function Call With Incorrect Argument Type Works

Root Cause

The root cause lies in specifying an argument for a function call that does not match the expected data type, leading to undefined behavior or errors.

Attack Flow

1. An attacker identifies a function call with incorrect argument types.
2. The application processes the invalid arguments, causing unexpected results.
3. This may lead to crashes, data corruption, or other security issues.

Prerequisites to Exploit

• Function calls must have mismatched parameter types.
• Incorrect handling of these mismatches by the runtime environment.

Vulnerable Code

def process_data(data):
    print("Processing:", data)

process_data(123)  # Incorrect argument type: integer instead of expected string or object

This code demonstrates a function call with an incorrect argument type, leading to potential issues.

Secure Code

def process_data(data):
    if not isinstance(data, str):
        raise ValueError("Expected data as string")
    print("Processing:", data)

process_data("data")  # Correct argument type: string

The secure code ensures that the function call has the correct data type by validating input before processing.

Business Impact of Function Call With Incorrect Argument Type

Confidentiality

• Data may be exposed due to unexpected behavior or crashes.
• Example: Sensitive information could be inadvertently logged or displayed.

Integrity

• Application state can become corrupted, leading to incorrect data handling.
• Example: Inconsistent database entries due to improper parameter handling.

Availability

• The application might crash or behave unpredictably, affecting user experience and system stability.
• Example: Frequent crashes causing downtime for users.

Function Call With Incorrect Argument Type Attack Scenario

1. An attacker identifies a function call with incorrect argument types in the codebase.
2. They exploit this by providing invalid arguments to cause unexpected behavior.
3. The application processes these invalid arguments, leading to potential data corruption or system crashes.
4. This results in degraded service availability and possible exposure of sensitive information.

How to Detect Function Call With Incorrect Argument Type

Manual Testing

• Review function calls for correct argument types.
• Ensure all parameters match expected data types.
• Test with invalid arguments to verify error handling.

Automated Scanners (SAST / DAST)

Static analysis can detect type mismatches in function calls, while dynamic testing is needed to observe runtime behavior and validate error handling.

PenScan Detection

PenScan’s scanner engines such as ZAP, Nuclei, Wapiti, Nikto, SSLyze, Dalfox, and Nmap can identify potential issues related to incorrect argument types.

False Positive Guidance

A false positive occurs when a function call with an invalid type is flagged but the application handles it correctly through error checking or default values.

How to Fix Function Call With Incorrect Argument Type

• Ensure all function calls match expected parameter types.
• Implement strict typing and validation for input data.
• Use static analysis tools to catch type mismatches during development.
• Test with various inputs to ensure robustness against unexpected arguments.

Framework-Specific Fixes for Function Call With Incorrect Argument Type

Python (Django)

def process_data(data):
    if not isinstance(data, str):
        raise ValueError("Expected data as string")
    print("Processing:", data)

This example ensures that the function call has the correct data type by validating input before processing.

How to Ask AI to Check Your Code for Function Call With Incorrect Argument Type

Function Call With Incorrect Argument Type Best Practices Checklist

✅ Ensure all function calls match expected parameter types. ✅ Use static analysis tools to catch type mismatches during development. ✅ Implement strict typing and validation for input data. ✅ Test with various inputs to ensure robustness against unexpected arguments. ✅ Document expected argument types in function definitions.

Function Call With Incorrect Argument Type FAQ

How does function call with incorrect argument type occur?

It occurs when a function is called with an argument that has the wrong data type, leading to potential vulnerabilities or errors in application logic.

Why is it important to prevent function call with incorrect argument type?

Preventing this issue ensures the integrity and reliability of software by avoiding unexpected behavior or crashes due to mismatched types.

How can I detect function call with incorrect argument type in my code?

Use static analysis tools that check for type mismatches between function calls and their definitions, as well as manual review focusing on parameter usage.

What are the business impacts of function call with incorrect argument type vulnerabilities?

These vulnerabilities can lead to application crashes, data corruption, or unexpected behavior affecting user experience and system stability.

How do I fix function call with incorrect argument type in my codebase?

Ensure that all function calls match the expected parameter types by reviewing and updating the definitions as necessary.

What are some common mistakes to avoid when dealing with function call with incorrect argument type?

Avoid relying on implicit type conversions or assuming default values without proper validation.

How can I prevent function call with incorrect argument type during development?

Implement strict typing and thorough testing, including unit tests that check for correct parameter types.

Vulnerabilities Related to Function Call With Incorrect Argument Type

References

• MITRE: CWE-686
• NVD

Scan Your Own Site

Manual code review catches what you know to look for. An automated scan catches what you didn’t. Scan your own website using PenScan to find Function Call With Incorrect Argument Type and other risks before an attacker does.