Validate Input Sanitization using Github Copilot

function sanitizeInput(input) {
    return input.replace(/<script.*?>.*?<\/script>/gi, '');
}

The input sanitization function aims to mitigate XSS by removing `<script>` tags from user inputs. However, there are several concerns:

1. Inadequate Filtering: The function only targets explicit `<script>` tags. XSS attacks can be conducted through other tags and events, such as `<img onerror=...>` or `<div onclick=...>`. Attackers can bypass the filter by using different tags or encoding methods.

2. Blacklist Approach: Relying on a blacklist (specifying what to remove) is less secure compared to a whitelist approach (specifying what to allow). Consider using a whitelist of safe characters or tags and encoding or removing all other inputs.

3. Regular Expression Limitations: The use of regular expressions to filter out malicious scripts can be circumvented. Complex or obfuscated scripts may not match the pattern and could still execute.

4. Escaping Data: Instead of removing potentially harmful characters, it's often safer to escape user input. This means converting special characters to HTML entities (e.g., converting `<` to `&lt;`).

5. Using Secure Libraries: Utilize established libraries for sanitization, such as OWASP's Java Encoder for Java or DOMPurify for JavaScript, which are more likely to be up-to-date against various XSS attack vectors.

6. Contextual Output Encoding: Apply context-specific encoding when rendering user input in HTML, JavaScript, URL, or CSS contexts. This approach ensures that the input is safe to display in the given context.

To enhance the function’s effectiveness against XSS, consider the following revised version:

```javascript
function sanitizeInput(input) {
    return input.replace(/[^a-zA-Z0-9 ]/g, '');  // Whitelist alphanumeric characters and spaces
}

function sanitizeInput(input) {
    return DOMPurify.sanitize(input);
}