Return to Data validation

Input Validation is a crucial security practice that ensures data received from users or other sources conforms to expected formats and values before being processed by a system. It helps prevent a variety of security vulnerabilities, such as SQL injection, cross-site scripting (XSS), and buffer overflow attacks, by filtering and validating input data to ensure it is both safe and meaningful.

• Security: Proper input validation prevents malicious data from being processed, which can protect against common attacks like SQL injection and XSS. By validating input data, you reduce the risk of compromising the application’s integrity and security.
• Data Integrity: Ensuring that inputs conform to expected formats and constraints helps maintain the accuracy and consistency of the data stored and processed by the system. This prevents issues that might arise from invalid or corrupted data.

• Client-Side Validation: This type of validation occurs in the user's browser before the data is sent to the server. It can provide immediate feedback to users and reduce the amount of invalid data sent to the server, but should not be solely relied upon as it can be bypassed by attackers.
• Server-Side Validation: Validation performed on the server after the data has been submitted. This is essential for security, as it ensures that all data is thoroughly checked before being processed or stored. Server-side validation is the final line of defense against invalid or malicious input.

• Whitelist Input Validation: Define and enforce a whitelist of acceptable input values and formats. Reject any input that does not match the expected criteria. This approach is more secure than using blacklists of known malicious inputs.
• Sanitization: In addition to validation, sanitizing input data by removing or escaping potentially dangerous characters helps prevent vulnerabilities such as injection attacks.
• Error Handling: Implement appropriate error handling to manage invalid inputs gracefully. Provide users with clear and actionable error messages without revealing sensitive information about the internal workings of the system.

• https://owasp.org/www-community/controls/Input_Validation
• https://en.wikipedia.org/wiki/Input_validation
• https://www.sans.org/white-papers/370/