Study the scenario and complete the questions that follow:

E$-$Commerce Platform

You are working for a leading e$-$commerce platform that allows users to purchase products online. Your platform provides a feature$-$rich web application where customers can search for products, add them to their shopping carts, and complete purchases using various payment methods. Recently, your company has noticed a surge in suspicious activities, including unauthorized access attempts and fraudulent transactions. Upon investigation, your cybersecurity team discovers that attackers are exploiting vulnerabilities in your web application to execute command injection, script injection, and memory injection attacks.

Command Injection:

Attackers are leveraging vulnerabilities in your platform's search functionality to inject malicious commands into the underlying operating system. By manipulating input parameters, attackers can execute arbitrary commands on the server, potentially gaining unauthorized access to sensitive data or compromising the integrity of the system.

Script Injection:

Attackers are exploiting vulnerabilities in your platform's user input forms to inject malicious scripts, such as JavaScript code, into web pages viewed by other users. These scripts can steal session cookies, redirect users to phishing sites, or perform other malicious activities without their knowledge

Memory Injection:

Attackers are exploiting vulnerabilities in your platform's memory management processes to inject malicious code into the memory space of running applications. This technique allows attackers to bypass security controls and execute arbitrary code with elevated privileges, potentially compromising the entire system.

As a software engineer responsible for securing the e$-$commerce platform, you must identify and mitigate these vulnerabilities to prevent further exploitation by attackers.

Source: Bokaba, G$,2024$

$3\mathrm{.}1$

What measures can you implement to mitigate script injection attacks in the e$-$commerce platform?

Note Discuss the importance of input sanitization, output encoding, and content security policies in preventing cross$-$site scripting $($XSS$)$ vulnerabilities.

$(5$ Marks$)$

$3\mathrm{.}2$

You are tasked with developing a script to validate user input in a web application to prevent command injection attacks. How would you approach designing and implementing this script, considering the following requirements?

$$ The script should sanitise$[$TT$1]$ user input to remove any potentially malicious characters or commands.

$$ It should validate input against a whitelist of allowed characters or patterns to ensure that only safe input is accepted.

$$ The script should be implemented using a scripting language of your choice, such as Python, JavaScript, or Bash, depending on the application environment.

Provide a detailed explanation of your approach, including code snippets and examples, to demonstrate how you would address each requirement effectively.

$(25$ Marks$)$