CWE-511: Logic/Time Bomb

What is Logic/Time Bomb?

• Overview: Logic/Time Bomb (CWE-511) is a vulnerability where a program is designed with hidden code that activates under certain conditions or after a specific time, disrupting normal operations.

• Exploitation Methods:

• Attackers can exploit this by embedding malicious logic within software that triggers based on pre-set conditions.
• Common attack patterns include inserting code that activates after a specific date or when particular data inputs occur.

• Security Impact:

• Direct consequences include system crashes, data loss, or performance degradation.
• Potential cascading effects involve extended downtime and potential spread of malicious operations to connected systems.
• Business impact may include financial loss, damage to reputation, and legal liabilities due to data breaches or service disruptions.

• Prevention Guidelines:

• Specific code-level fixes involve regular code reviews and audits to detect and remove suspicious logic.
• Security best practices include implementing rigorous version control and change management processes.
• Recommended tools and frameworks include static analysis tools that scan for unusual code patterns and behavior.

Corgea can automatically detect and fix Logic/Time Bomb in your codebase. [Try Corgea free today](https://corgea.app).

Technical Details

Likelihood of Exploit: Not specified

Affected Languages: Not Language-Specific

Affected Technologies: Mobile

Vulnerable Code Example

Certainly! Here is the improved content for the code examples related to CWE-511 (Logic/Time Bomb), addressing the issues you mentioned:

import datetime

def check_license():
    # This function disrupts service after a specific date
    expiration_date = datetime.datetime(2023, 10, 1)  # Hardcoded expiration date
    if datetime.datetime.now() > expiration_date:
        raise Exception("Service expired. Please contact support.")  # Service disruption

def perform_service():
    check_license()
    print("Service is running...")

perform_service()

Vulnerability Explanation:

• Logic/Time Bomb Vulnerability: The code contains a logic bomb that disrupts service after a specific date (October 1, 2023). This hardcoded date can lead to a denial of service, as it abruptly stops the service without a proper mechanism to renew or extend the license dynamically.

How to fix Logic/Time Bomb?

To fix this vulnerability:

1. Remove Hardcoded Dates: Avoid using hardcoded expiration dates. Instead, implement a dynamic license verification system.
2. Implement Proper Licensing Checks: Use a secure method to check license validity, such as querying a licensing server or database.
3. Log and Monitor: Log any issues with license validity and monitor them to take corrective actions without disrupting the service.

Fixed Code Example

import datetime
import logging

# Simulated function to check if a license is valid
def is_license_valid():
    # Replace with actual license verification logic, e.g., querying a license server
    return True  # Assume the license is valid for demonstration purposes

def check_license():
    if not is_license_valid():  # Use dynamic license check
        logging.error("License invalid. Please contact support.")  # Log error instead of raising an exception
        return False
    return True

def perform_service():
    if check_license():  # Only perform service if license is valid
        print("Service is running...")

perform_service()

Fix Explanation:

• Proper License Check: The fixed example uses a function is_license_valid() to dynamically check the license status, eliminating the hardcoded date.
• Logging Instead of Disruption: The code logs an error message if the license is invalid, allowing for corrective actions without abrupt service disruption.
• Control Flow: The service execution is controlled based on the license validity, ensuring that the service only runs when the license is valid, thus maintaining service availability.

This improved content ensures that the examples are realistic, clearly demonstrate the vulnerability and its fix, and adhere to best practices in Python programming.