CWE-920: Improper Restriction of Power Consumption

What is Improper Restriction of Power Consumption?

• Overview: Improper Restriction of Power Consumption, CWE-920, occurs when software does not limit its power usage in environments where power is a scarce resource, such as in embedded or mobile devices running on battery power, which can lead to device malfunction or increased costs.

• Exploitation Methods:

• Attackers can exploit this vulnerability by deliberately causing the application to consume excessive power.
• Common attack patterns include manipulating the software to perform unnecessary operations using components like the display, CPU, disk I/O, GPS, sound, microphone, or USB interface.

• Security Impact:

• Direct consequences include device shutdown or application failure due to rapid power depletion.
• Potential cascading effects include data loss, corruption, or reduced device lifespan.
• Business impact could involve increased operational costs, customer dissatisfaction, and potential damage to the brand's reputation.

• Prevention Guidelines:

• Implement code-level fixes by optimizing algorithms and reducing unnecessary resource usage.
• Follow security best practices such as power budgeting and limiting component usage to essential operations.
• Use recommended tools and frameworks that provide power monitoring and management features to track and optimize power consumption.

Corgea can automatically detect and fix Improper Restriction of Power Consumption 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

// Vulnerable code with detailed comments explaining the security issue

const http = require('http');
const server = http.createServer((req, res) => {
    // Simulate power-intensive operation without restriction
    while (true) {  // Busy-wait loop that consumes CPU power indefinitely
        // This loop can lead to excessive power consumption, especially on resource-constrained devices
        // It prevents the server from handling other requests efficiently, leading to denial of service
    }
    res.end('Hello, World!');
});

server.listen(3000, () => {
    console.log('Server is running on port 3000');
});

How to fix Improper Restriction of Power Consumption?

To fix the improper restriction of power consumption, it's important to ensure that your application does not perform unnecessary power-intensive operations, especially in environments with limited resources (e.g., battery-powered IoT devices). This can be achieved by:

1. Implementing Efficient Algorithms: Replace inefficient busy-wait loops with event-driven or asynchronous patterns that are power efficient.
2. Using Throttling or Debouncing: Limit the frequency of power-intensive operations using throttling or debouncing techniques.
3. Monitoring and Limiting Resource Usage: Implement resource monitoring and apply limits to prevent excessive power consumption.
4. Graceful Degradation: In scenarios where power is limited, the application should degrade functionality gracefully rather than consuming all available resources.

Fixed Code Example

// Fixed code with comments explaining the security controls implemented

const http = require('http');
const server = http.createServer((req, res) => {
    // Efficiently handle requests without indefinite power consumption
    // Using setTimeout to simulate an asynchronous operation
    setTimeout(() => {
        // Perform necessary operations here
        res.end('Hello, World!');
    }, 1000);  // Simulate a delay to mimic async operation, avoiding busy-wait

    // Example of throttling: limit the frequency of intensive operations
    const executeTask = throttle(() => {
        // Perform power-intensive task
        console.log('Task executed');
    }, 5000);  // Throttle to execute at most once in 5 seconds

    executeTask();
});

// Throttle function to limit the execution frequency
function throttle(fn, delay) {
    let lastCall = 0;
    return function(...args) {
        const now = new Date().getTime();
        if (now - lastCall >= delay) {
            lastCall = now;
            return fn(...args);
        }
    };
}

server.listen(3000, () => {
    console.log('Server is running on port 3000');
});

In this fixed example, we replaced the busy-wait loop with a setTimeout to mimic an asynchronous operation, which avoids indefinite power consumption. Additionally, we introduced a throttle function to limit the frequency of power-intensive tasks, ensuring they are executed sparingly and efficiently. This approach ensures the server can handle other requests effectively and reduces unnecessary power usage.