A penetration tester noticed special characters in a database table.
The penetration tester configured the browser to use an HTTP interceptor to verify that the front-end user registration web form accepts invalid input in the user's age field.
The developer was notified and asked to fix the issue.
Which of the following is the MOST secure solution for the developer to implement?
Click on the arrows to vote for the correct answer
A. B. C. D.B.
Out of the given options, the MOST secure solution for the developer to implement is Option C: IF $AGE != a-bA-Z!@#$%^&*()_+<>?:{}[] THEN CONTINUE.
Here's why:
Option A: IF $AGE == !@#$%^&*()_+<>?:{}[] THEN ERROR This option attempts to filter out special characters from the input field, but it only allows a specific set of special characters. This is not an effective solution because it doesn't account for other special characters that may be used in an attack. Attackers can easily bypass this filter by using a special character that is not included in the allowed set.
Option B: IF $AGE == [1234567890] {1,3} THEN CONTINUE This option only allows numeric values in the age field and limits the length to between 1 and 3 digits. While this may seem like a simple and effective solution, it is not a foolproof method. Attackers can still attempt to bypass this filter by using characters other than numbers or by inputting numbers that exceed the length limit.
Option C: IF $AGE != a-bA-Z!@#$%^&*()_+<>?:{}[] THEN CONTINUE This option is the most secure solution out of the given options. It allows all characters except for a specific set of special characters, which can help prevent attackers from injecting malicious code into the input field. It is important to note that this solution should be combined with additional security measures, such as input validation and sanitization, to ensure maximum protection against attacks.
Option D: IF $AGE == [1-0] {0,2} THEN CONTINUE. This option only allows numeric values in the age field and limits the length to between 0 and 2 digits. This is similar to Option B, and while it may seem like a simple solution, it still has limitations. Attackers can still attempt to bypass this filter by using characters other than numbers or by inputting numbers that exceed the length limit.
Overall, the best practice for developers is to use a combination of input validation, input sanitization, and output encoding to prevent attacks like cross-site scripting (XSS) and SQL injection.