Preventing Web Form Compromise

A.

The most likely solution to prevent the application compromise resulting from malformed data is input validation (option A). Input validation is a process of validating and sanitizing user input to ensure that it meets the expected format and does not contain any harmful or malicious content.

Malformed data can cause a variety of security issues, such as buffer overflow attacks, SQL injection attacks, and cross-site scripting attacks. These attacks can result in unauthorized access to sensitive information, data loss, or system damage.

Input validation can prevent such attacks by ensuring that the input data meets the expected format, length, and data type. For instance, if the application is expecting a numeric value, input validation can ensure that the user input is a number and not a string or any other data type. Input validation can also check for special characters and escape them or remove them to prevent injection attacks.

On the other hand, a proxy server (option B) is an intermediary server that sits between the client and the server and can be used to monitor and filter incoming traffic. While a proxy server can provide some level of security by hiding the server's IP address and filtering out unwanted traffic, it cannot prevent malformed data from reaching the application.

Stress testing (option C) is a technique used to test the application's performance under heavy load or stress. While stress testing can help identify potential vulnerabilities, it cannot prevent malformed data from reaching the application.

Encoding (option D) is a process of converting data from one format to another, such as converting plaintext to ciphertext for secure transmission. While encoding can provide some level of security, it cannot prevent malformed data from reaching the application.

In summary, the most effective solution to prevent application compromise resulting from malformed data is input validation, as it can ensure that the input data meets the expected format and does not contain any harmful or malicious content.