What is Function Call With Incorrect Variable (CWE-688)?

TL;DR: Function Call With Incorrect Variable or Reference as Argument (CWE-688) is a vulnerability where incorrect variables are passed to functions, leading to undefined behavior and quality degradation. Fixing this involves ensuring proper variable usage in function calls.

What is Function Call With Incorrect Variable or Reference as Argument?

Function Call With Incorrect Variable or Reference as Argument (CWE-688) is a type of vulnerability where incorrect variables are passed to functions, leading to undefined behavior. As defined by the MITRE Corporation under CWE-688, and classified by the OWASP Foundation under no official mapping…

Quick Summary

Function Call With Incorrect Variable or Reference as Argument occurs when a function call specifies an incorrect variable or reference as one of its arguments. This can lead to unexpected application crashes and quality degradation, making the system unreliable. Jump to: What is Function Call With Incorrect Variable or Reference as Argument? · Quick Summary · Overview · How It Works · Business Impact · Attack Scenario · Detection · Fixing · Framework-Specific Fixes · AI Check Prompt · Best Practices · FAQ · Related Vulnerabilities

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

Function Call With Incorrect Variable or Reference as Argument Overview

What: This is a vulnerability where incorrect variables are passed to functions, leading to undefined behavior.

Why it matters: It can cause unexpected application crashes and quality degradation, making the system unreliable.

Where it occurs: In any programming language that allows function calls with variable arguments.

Who is affected: Any developer or organization using such languages without proper validation mechanisms in place.

Who is NOT affected: Systems already using robust validation techniques to ensure correct argument passing.

How Function Call With Incorrect Variable or Reference as Argument Works

Root Cause

The root cause of this vulnerability lies in the incorrect assignment of variables or references when calling functions. This can occur due to coding errors, misunderstandings about variable types, or misuse of function parameters.

Attack Flow

1. An attacker identifies a vulnerable code path where incorrect arguments are passed to a function.
2. The attacker exploits this by manipulating input data to trigger the incorrect argument passing.
3. As a result, the application exhibits undefined behavior and potential crashes.

Prerequisites to Exploit

• The presence of a function call with an incorrectly specified variable or reference as an argument.
• Access to the codebase or ability to manipulate inputs that affect this call.

Vulnerable Code

def process_data(data):
    # Incorrectly passing 'data' instead of another required parameter
    return some_function(data)

process_data(some_input)

This example shows a function process_data incorrectly calling another function with the wrong variable as an argument, leading to undefined behavior.

Secure Code

def process_data(required_param):
    # Ensuring correct parameters are passed
    return some_function(required_param)

# Ensure proper validation before calling the function
if isinstance(some_input, required_type):
    process_data(some_input)
else:
    raise ValueError("Invalid input type")

This secure version ensures that only valid and expected types of arguments are passed to functions.

Business Impact of Function Call With Incorrect Variable or Reference as Argument

Quality Degradation: The application may become unreliable, leading to frequent crashes and unexpected behavior.

• Example: A function expecting a specific data type receives an incorrect one, causing the program to crash.
• Financial impact: Increased maintenance costs due to frequent bug fixes.
• Compliance impact: Non-compliance with quality assurance standards can lead to regulatory penalties.
• Reputation impact: Frequent crashes and poor performance damage user trust.

Function Call With Incorrect Variable or Reference as Argument Attack Scenario

1. An attacker identifies a function call that passes incorrect variables.
2. The attacker manipulates input data to trigger the incorrect argument passing.
3. As a result, the application exhibits undefined behavior and potential crashes.
4. This leads to service disruptions and loss of user trust.

How to Detect Function Call With Incorrect Variable or Reference as Argument

Manual Testing

• [ ] Review function calls for correct variable usage.
• [ ] Validate arguments before passing them to functions.
• [ ] Check documentation and comments for consistency with actual code.

Automated Scanners (SAST / DAST)

Static analysis tools can detect incorrect argument types, while dynamic testing is needed to verify runtime behavior.

PenScan Detection

PenScan’s scanner engines such as ZAP and Wapiti can identify potential issues by analyzing function calls during static analysis.

False Positive Guidance

False positives may occur if the code uses type hints or annotations correctly but does not actually enforce them at runtime.

How to Fix Function Call With Incorrect Variable or Reference as Argument

• Ensure proper validation of arguments before passing them to functions.
• Use type hinting and enforcement mechanisms where available.
• Implement comprehensive testing strategies to catch such issues early.

Framework-Specific Fixes for Function Call With Incorrect Variable or Reference as Argument

Python/Django

def process_data(required_param):
    # Ensure correct parameters are passed
    return some_function(required_param)

# Validate input before calling the function
if isinstance(some_input, required_type):
    process_data(some_input)
else:
    raise ValueError("Invalid input type")

How to Ask AI to Check Your Code for Function Call With Incorrect Variable or Reference as Argument

Function Call With Incorrect Variable or Reference as Argument Best Practices Checklist

✅ Ensure all function calls use correct variables or references. ✅ Implement type checking and enforcement mechanisms. ✅ Regularly review and test your code for such issues.

Function Call With Incorrect Variable or Reference as Argument FAQ

How does function call with incorrect variable or reference as argument occur?

This vulnerability arises when a program calls a function but specifies the wrong variable or reference as an argument.

What are the consequences of function call with incorrect variable or reference as argument?

It can lead to undefined behavior and may result in quality degradation, making the application unreliable and difficult to maintain.

How do I detect function call with incorrect variable or reference as argument?

Detect this vulnerability through manual testing by reviewing code for improper function calls or automated scanning using static analysis tools.

What is the impact of function call with incorrect variable or reference as argument on system availability?

This issue can cause unexpected crashes and disruptions, impacting the overall availability of the application.

How do I fix function call with incorrect variable or reference as argument in Python code?

Ensure that all function calls use the correct variables or references by thoroughly reviewing and testing your code.

What are some best practices to prevent function call with incorrect variable or reference as argument?

Regularly review and test your code, ensure proper documentation of function parameters, and maintain a robust development process.

Can you provide an example of vulnerable code for function call with incorrect variable or reference as argument?

A common example is passing the wrong variable to a function that expects a specific type or value.

Vulnerabilities Related to Function Call With Incorrect Variable or Reference as Argument

References

• MITRE
• 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 Variable or Reference as Argument and other risks before an attacker does.