How do you secure user input on the front-end?

3 Escape user input

Escaping is the process of adding or changing characters in the user input to prevent them from being interpreted as code or commands by the browser or the server. Escaping can help prevent code injection, command injection, and other attacks that exploit user input to manipulate or compromise your system. For example, you can escape user input by using backslashes, quotes, or other symbols that can indicate that the input is a string or a literal value, not a code or a command. Escaping can be done on the client-side, the server-side, or both, depending on where and how the input is used. However, escaping alone is not enough, as it can also introduce errors or vulnerabilities if not done correctly or consistently. Therefore, you should always use escaping in conjunction with validation and sanitization.

4 Encode user input

Encoding is the process of converting the user input from one format to another to make it suitable for transmission or storage. Encoding can help prevent data corruption, data loss, or data leakage that can occur when the user input is not compatible with the target format or system. For example, you can encode user input by using base64, URL, or other methods that can transform the input into a standard or uniform format that can be easily transmitted or stored. Encoding can be done on the client-side, the server-side, or both, depending on the source and destination of the input. However, encoding alone is not enough, as it can also create confusion or errors if not done properly or appropriately. Therefore, you should always use encoding in conjunction with validation, sanitization, and escaping.

5 Test user input

Testing is the process of verifying whether the user input is secure and functional in different scenarios and environments. Testing can help identify and fix any errors, bugs, or vulnerabilities that can affect the performance or security of your website or app. For example, you can test user input by using automated tools, manual methods, or user feedback that can simulate or evaluate various input types, values, and behaviors. Testing can be done on the client-side, the server-side, or both, depending on the scope and complexity of the input. However, testing alone is not enough, as it can also miss or overlook some issues or risks that are not obvious or predictable. Therefore, you should always use testing in conjunction with validation, sanitization, escaping, and encoding.

6 Update user input

Updating is the process of keeping the user input secure and functional over time by applying the latest changes, improvements, or fixes. Updating can help prevent outdated, obsolete, or insecure input that can cause problems or threats to your website or app. For example, you can update user input by using version control, dependency management, or other tools that can monitor and maintain the quality and security of your code and libraries. Updating can be done on the client-side, the server-side, or both, depending on the frequency and urgency of the changes. However, updating alone is not enough, as it can also introduce new errors or vulnerabilities if not done carefully or correctly. Therefore, you should always use updating in conjunction with validation, sanitization, escaping, encoding, and testing.

7 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?