{keyword} Union All Select Null,null,null,null,null,null,null,null-- Ppsq May 2026
Once an attacker knows there are 8 columns, they can replace the NULL values with commands to extract sensitive data, such as usernames, passwords, or database versions. SQL injection UNION attacks | Web Security Academy
: When the number of NULL s matches exactly (in your case, 8 columns), the page will load normally or show an extra blank row, confirming the database structure. Why This Matters Once an attacker knows there are 8 columns,
: Attackers use NULL because it is compatible with almost every data type (integers, strings, dates), making it the "safest" way to avoid syntax errors while testing column counts. The string you provided is a classic payload
The string you provided is a classic payload. It is not a feature of a specific software product but rather a technique used by security researchers and attackers to probe databases for vulnerabilities. Purpose of the Payload such as usernames
: If the number of NULL values does not match the original query's column count, the server usually returns an error (like a 500 Internal Server Error).
