querysanitization

Query sanitization is the process of cleaning or transforming user-supplied input that will be used to construct a query to a database, search engine, or other data processing system. The aim is to prevent unintended behavior such as injection attacks, data leakage, or performance degradation by removing or neutralizing dangerous input and by enforcing expected formats and lengths. It is commonly applied to web applications that accept query strings, search terms, or API parameters.

Common techniques include validation against a whitelist of allowed values or patterns; escaping or encoding special characters according to the syntax of the target backend; and using parameterized queries or prepared statements that separate data from code. Context matters: escaping needs to be applied for the specific query language, and in outputs (such as HTML) the input should be encoded for the output context. Other practices include input normalization, length checks, and removing or rejecting disallowed operators or control characters. In many ecosystems, parameterized queries with bound parameters provide stronger protection than ad-hoc sanitization.

It is not a substitute for proper access control, authentication, and least-privilege database permissions, nor for comprehensive input validation and secure coding practices. Sanitization should be complemented by defensive measures such as escaping at render time, using ORM or query builders, and regular security testing. The concept applies across contexts, including SQL, NoSQL, search syntax, and command shells, each requiring its own rules for safe input handling.