This specific string is designed to trick a web application into running an unintended database command:
: Ensure the database user account has the bare minimum permissions necessary to function.
The phrase you provided, -9718 UNION ALL SELECT 34,34,34,34,34,34,34,34,34,34# , is a classic example of , a technique used to probe a database for vulnerabilities. Understanding the Syntax -9718 UNION ALL SELECT 34,34,34,34,34,34,34,34,34,34#
: This SQL operator combines the result sets of two or more SELECT statements into a single result.
: In many SQL dialects like MySQL, the hash symbol indicates the start of a comment, which "comments out" the rest of the original, legitimate query so it doesn't cause a syntax error. Security Implications This specific string is designed to trick a
: The repeated "34" is used to determine the number of columns required by the original query. If the number of values (in this case, ten) doesn't match the original table's columns, the database will return an error.
This pattern is often the "reconnaissance" phase of an attack. Once an attacker knows how many columns a table has and which ones are displayed on the screen, they can replace the dummy numbers with commands to extract sensitive data, such as usernames, passwords, or system configurations. How to Prevent These Attacks To protect your applications, developers should: : In many SQL dialects like MySQL, the
: This likely represents a dummy or non-existent ID. By using an ID that doesn't exist, the attacker ensures the first part of the query returns no results, making the "injected" results from the second part more visible.