Sanitize inputs to block special characters like ) , # , and -- .
Access sensitive information like user credentials, emails, or financial records.
The input {KEYWORD}) UNION ALL SELECT NULL,NULL# is a classic payload. This specific string is designed to break out of a developer-defined query and append a UNION statement, allowing an attacker to retrieve data from other tables or probe the database structure [1]. 2. Technical Analysis {KEYWORD}) UNION ALL SELECT NULL,NULL#
The # character (used in MySQL/MariaDB) comments out the rest of the legitimate query, preventing syntax errors from trailing code [3]. 3. Potential Risk An attacker successfully using this technique can:
Identify the database version and schema to plan a larger breach [1]. 4. Recommended Fixes Sanitize inputs to block special characters like )
Implement parameterized queries (e.g., using PDO in PHP or PreparedStatement in Java). This ensures the database treats the input as text, not executable code [4].
Security Audit Report: SQL Injection Vulnerability Critical / High Priority Location: Query Parameter {KEYWORD} 1. Vulnerability Summary This specific string is designed to break out
UNION ALL SELECT NULL,NULL is used to determine the number of columns in the original query's SELECT statement. If the page loads without an error, the attacker knows the original table has exactly two columns [2].