Final answer:
Parameterized queries are the countermeasure for prepared statements in database management systems, helping to prevent SQL injection attacks by separating the SQL command structure from the data values.
Step-by-step explanation:
The countermeasure for a prepared statement is Parameterized queries. A prepared statement is a feature used in database management systems to execute the same or similar database statements repeatedly with high efficiency. Parameterized queries, also known as prepared statements, are a method of executing SQL queries where the SQL command uses placeholders for parameters and the parameter values are supplied later.
This tactic helps prevent SQL injection attacks, as it separates the SQL logic from the data being passed. It's important to note that while input validation is crucial for securing forms and data input, and output encoding can prevent Cross-site Scripting (XSS) attacks, these are not specific countermeasures to the issue of SQL injection that prepared statements address.
Moreover, while stored procedures can offer some level of security by encapsulating the SQL logic within the database, they are not a direct countermeasure to SQL injection like parameterized queries.