The primary goal of this specific syntax is to returned by the original, legitimate database query.
: 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
: This is a SQL comment marker that tells the database to ignore the rest of the original query, preventing errors from leftover code. How it Works
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
: This command attempts to append a new set of results to the original query's output.
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
: An attacker starts with one NULL and keeps adding more (e.g., NULL, NULL , then NULL, NULL, NULL ).
: 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).
{keyword} Union All Select Null,null,null,null,null,null,null,null-- Ppsq Page
The primary goal of this specific syntax is to returned by the original, legitimate database query.
: 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
: This is a SQL comment marker that tells the database to ignore the rest of the original query, preventing errors from leftover code. How it Works The primary goal of this specific syntax is
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
: This command attempts to append a new set of results to the original query's output. How it Works
The string you provided is a classic payload
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
: An attacker starts with one NULL and keeps adding more (e.g., NULL, NULL , then NULL, NULL, NULL ). Once an attacker knows there are 8 columns,
: 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).