What is Use of Inherently Dangerous Function (CWE-242)?

TL;DR: Use of Inherently Dangerous Function (CWE-242) is a security vulnerability that occurs when developers use unsafe functions without adequate safeguards, leading to potential data corruption or unauthorized access. Fix it by replacing dangerous functions with safer alternatives.

What is Use of Inherently Dangerous Function?

Use of Inherently Dangerous Function (CWE-242) is a type of vulnerability that occurs when a function with known security risks is used without proper safeguards. As defined by the MITRE Corporation under CWE-242, and classified by the OWASP Foundation as not directly mapped.

Quick Summary

Use of Inherently Dangerous Function (CWE-242) is a critical issue where developers use functions that are inherently unsafe, leading to potential security vulnerabilities such as data corruption or unauthorized access. This vulnerability can have severe business impacts, including financial losses and reputational damage. Jump to: Overview · How it Works · Business Impact · Attack Scenario · Detection · Fixes

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

Use of Inherently Dangerous Function Overview

What

Use of Inherently Dangerous Function (CWE-242) occurs when a function with known security risks is used without proper safeguards, leading to potential data corruption or unauthorized access.

Why it matters

This vulnerability can lead to various security issues such as data corruption, unauthorized access, and system instability. It poses significant business risks including financial losses and reputational damage.

Where it occurs

It can occur in any programming language where developers use functions that are inherently dangerous without proper validation or error handling.

Who is affected

Developers and organizations using unsafe functions without adequate safeguards are at risk of security vulnerabilities.

Who is NOT affected

Applications that avoid the usage of prohibited API functions, and those implementing strict coding standards to prevent such issues.

How Use of Inherently Dangerous Function Works

Root Cause

The root cause lies in calling a function that cannot be guaranteed to work safely under all circumstances. This often results from inadequate design or implementation practices.

Attack Flow

1. An attacker identifies the usage of an inherently dangerous function within the application codebase.
2. The attacker exploits the lack of proper safeguards around this function to perform malicious actions such as data corruption or unauthorized access.
3. The system is compromised due to the absence of robust validation and error handling mechanisms.

   Prerequisites to Exploit

   • Presence of a vulnerable function call in the application’s source code.
   • Lack of proper input validation or error handling for that function.

     Vulnerable Code

     def unsafe_function(input):
      # Inherently dangerous function usage without safeguards
      system_call(input)
     

     This code demonstrates an insecure practice where a potentially harmful system call is made directly with user-provided data, leading to potential security vulnerabilities.

Secure Code

def safe_function(input):
    # Ensure input validation and proper error handling before making the system call
    if validate_input(input):
        system_call(securely_prepared_data)

The secure code ensures that input is properly validated and prepared before being passed to a potentially dangerous function, mitigating security risks.

Business Impact of Use of Inherently Dangerous Function

Confidentiality

Data confidentiality may be compromised due to unauthorized access or data leakage.

Integrity

System integrity can be affected by data corruption or manipulation through unsafe function usage.

Availability

The availability and stability of the system may be impacted, leading to service disruptions.

Use of Inherently Dangerous Function Attack Scenario

1. An attacker identifies a vulnerable function call in the application’s source code that lacks proper safeguards.
2. The attacker exploits this vulnerability by injecting malicious input data into the unsafe function.
3. As a result, the system is compromised, leading to unauthorized access or data corruption.

How to Detect Use of Inherently Dangerous Function

Manual Testing

• Review the codebase for usage of prohibited API functions.
• Verify that all calls to these functions are properly validated and error-handled.

  Automated Scanners (SAST / DAST)

  Static analysis tools can identify potential CWE-242 issues, while dynamic testing helps confirm actual vulnerabilities in runtime environments.

  PenScan Detection

  PenScan’s scanner engines such as ZAP, Nuclei, Wapiti, Nikto, SSLyze, Dalfox, and Nmap can detect Use of Inherently Dangerous Function.

  False Positive Guidance

  False positives may occur if the function is used correctly with proper safeguards in place. Ensure that any findings are validated against actual usage contexts.

How to Fix Use of Inherently Dangerous Function

• Identify a list of prohibited API functions and prohibit their use.
• Provide safer alternatives for these functions.
• Implement strict coding standards and automated tools to prevent the usage of dangerous functions.

Framework-Specific Fixes for Use of Inherently Dangerous Function

Python/Django Example

def safe_function(input):
    if validate_input(input):
        system_call(securely_prepared_data)

This example demonstrates how to use proper validation and error handling in a Python application, ensuring the secure usage of potentially dangerous functions.

How to Ask AI to Check Your Code for Use of Inherently Dangerous Function

Review the following [language] code block for potential CWE-242 Use of Inherently Dangerous Function vulnerabilities and rewrite it using safer alternatives: [paste code here]

Use of Inherently Dangerous Function Best Practices Checklist

✅ Identify a list of prohibited API functions. ✅ Provide safer alternatives for these functions. ✅ Implement strict coding standards to prevent the usage of dangerous functions.

Use of Inherently Dangerous Function FAQ

How does Use of Inherently Dangerous Function occur in real-world applications?

It occurs when developers use functions that are inherently unsafe and can lead to security vulnerabilities, such as those that lack proper input validation or error handling.

What is the root cause of Use of Inherently Dangerous Function?

The root cause is calling a function that cannot be guaranteed to work safely under all circumstances, often due to inadequate design or implementation practices.

How can I detect Use of Inherently Dangerous Function in my codebase?

You can use static analysis tools and manual code reviews to identify the usage of dangerous functions and ensure they are replaced with safer alternatives.

What is an example of a prohibited function that should not be used?

Functions like gets() or unsafe file operations should be avoided in favor of more secure alternatives such as fgets() or proper error handling mechanisms.

How can I prevent Use of Inherently Dangerous Function in my application?

Implement strict coding standards, use automated tools to identify and ban dangerous functions, and ensure developers are trained on safe programming practices.

What is the impact of a successful attack exploiting Use of Inherently Dangerous Function?

The impact can vary but often includes unauthorized access, data corruption, or system instability, depending on the specific function being misused.

How does PenScan help in detecting and preventing Use of Inherently Dangerous Function?

PenScan’s automated scanners can identify potential instances of dangerous functions and provide recommendations for remediation to ensure your application is secure.

Vulnerabilities Related to Use of Inherently Dangerous Function

| CWE | Name | Relationship | |—|—|—| | CWE-1177 | Use of Prohibited Code (ChildOf) |

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 Use of Inherently Dangerous Function and other risks before an attacker does.