To answer this question, you need to understand the concept of input validation and the vulnerabilities mentioned in the options.
Input validation is the process of checking the user input to ensure that it meets the expected format and constraints. It is a common security practice to prevent various types of attacks.
Let's go through each option to understand why it can or cannot be handled by input validation:
Option A) Cross-site Scripting (XSS) - This option can be handled by input validation. Input validation can help prevent users from entering malicious scripts or HTML tags in the input fields, which can be executed by other users visiting the website.
Option B) Injection Flaws - This option can be handled by input validation to some extent. Input validation can help prevent common injection attacks, such as SQL injection or command injection, by properly sanitizing and validating user input. However, it is important to note that input validation alone may not be sufficient to completely mitigate injection flaws. Additional security measures like parameterized queries, stored procedures, and code review should also be implemented.
Option C) Privilege Escalation - This option cannot be handled by input validation alone. Privilege escalation is a vulnerability that allows an attacker to gain higher privileges than originally assigned to them. Input validation focuses on ensuring the integrity and safety of user input, but it does not directly address privilege management or access control issues.
Option D) None of the above - This is the correct answer. Among the given options, privilege escalation is the vulnerability that cannot be handled by input validation.
In conclusion, the correct answer is option C) Privilege Escalation. Input validation can help mitigate vulnerabilities like cross-site scripting (XSS) and injection flaws, but it does not directly address privilege escalation.