CWE-453: Insecure Default Variable Initialization

What is Insecure Default Variable Initialization?

• Overview: Insecure Default Variable Initialization occurs when software initializes an internal variable with a value that is less secure than possible, potentially exposing the system to vulnerabilities.

• Exploitation Methods:

• Attackers can exploit this vulnerability by leveraging the insecure default values to bypass security checks or gain unauthorized access.
• Common attack patterns include using default credentials, exploiting uninitialized values that default to permissive settings, or predicting default values to manipulate application behavior.

• Security Impact:

• Direct consequences of successful exploitation may include unauthorized access, privilege escalation, or information disclosure.
• Potential cascading effects include the compromise of other systems dependent on the insecure application, leading to broader network intrusion.
• Business impact could involve data breaches, loss of customer trust, legal liabilities, and financial losses due to compromised systems.

• Prevention Guidelines:

• Specific code-level fixes include initializing variables with the most restrictive or secure values possible and avoiding hardcoded default credentials.
• Security best practices involve conducting regular security audits, implementing secure coding guidelines, and ensuring thorough testing for default settings.
• Recommended tools and frameworks include static analysis tools to detect insecure defaults and security-focused frameworks that enforce secure defaults during development.

Corgea can automatically detect and fix Insecure Default Variable Initialization in your codebase. [Try Corgea free today](https://corgea.app).

Technical Details

Likelihood of Exploit: Not specified

Affected Languages: PHP, Not Language-Specific

Affected Technologies: Not specified

Vulnerable Code Example

<?php
// Vulnerable: Using an insecure default password for the database connection
\$databaseConfig = [
    'host' => 'localhost',
    'user' => 'admin',
    'password' => 'password123', // Insecure default password
    'dbname' => 'myapp'
];

// Potentially insecure connection due to default password being easily guessed
\$connection = new mysqli(\$databaseConfig['host'], \$databaseConfig['user'], \$databaseConfig['password'], \$databaseConfig['dbname']);
?>

Explanation of Vulnerability:

• Insecure Default Variable Initialization: The default password password123 is weak and commonly used, making it easy for attackers to guess and gain unauthorized access to the database.
• Impact: This can lead to unauthorized data access, data manipulation, and even complete database compromise.

How to fix Insecure Default Variable Initialization?

To fix this vulnerability:

• Use a strong, unique password that is not hardcoded directly in the codebase.
• Store sensitive configurations, such as database credentials, in environment variables or secure configuration files that are not exposed in the code repository.
• Initialize variables with secure defaults or ensure they are set securely during deployment.

Fixed Code Example

<?php
// Fixed: Utilizing environment variables for secure database credentials
\$databaseConfig = [
    'host' => getenv('DB_HOST') ?: 'localhost',
    'user' => getenv('DB_USER') ?: 'admin',
    'password' => getenv('DB_PASSWORD'), // Securely fetched from environment variable
    'dbname' => getenv('DB_NAME') ?: 'myapp'
];

// Secure connection with credentials stored outside the codebase
\$connection = new mysqli(\$databaseConfig['host'], \$databaseConfig['user'], \$databaseConfig['password'], \$databaseConfig['dbname']);
?>

Explanation of Fix:

• Environment Variables: The credentials are now retrieved from environment variables, which should be set securely on the server where the application is deployed.
• No Hardcoded Passwords: By eliminating hardcoded passwords, the risk of exposing sensitive data through the codebase is minimized.
• Secure Defaults: The code provides a mechanism for using defaults that can be overridden by environment variables, ensuring flexibility and security.

Best Practices:

• Ensure that environment variables are not exposed in the code repository or logs.
• Use a secure method to manage and store environment variables, such as a secrets management tool.
• Regularly update and rotate credentials to maintain security.