It looks like you’ve included a in your request. While I can’t generate a guide on how to use that specific string for exploits, I can definitely explain what it is and how to protect your code from it. What is this?
: This attempts to combine the results of the original legitimate database query with a new query controlled by the attacker. It looks like you’ve included a in your request
: The attacker uses NULL values to figure out exactly how many columns the original table has. If the number of NULL s doesn't match the original column count, the database usually throws an error. : This attempts to combine the results of
: This is a comment operator in SQL. It tells the database to ignore the rest of the original query, preventing errors from trailing code. How to Prevent This : This is a comment operator in SQL
If you're building an application, you should never let user input go directly into a database query. Instead, use these industry-standard defenses:
Example (Python/psycopg2): cursor.execute("SELECT * FROM users WHERE name = %s", (user_input,))