Becoming the Hacker

Async data exfiltration

There is one more challenge with this particular type of vulnerability. Its asynchronous nature makes it impossible to use traditional methods for data exfiltration. While the query may execute successfully and the SQL server will delay the query result, we'd never be able to measure this, as the application that we are targeting does not wait for the SQL server response and returns immediately.

We have to be a bit more clever to extract data and successfully compromise the target. MS SQL server, MySQL, PostgreSQL, and others all have ways to accomplish our goal. We'll just go over an MS SQL method, but with a little creativity, any database engine can bend to the attacker's will. It's also important to remember that this ...