Null,null,null,null,null,null,null,null From Msysaccessobjects-- Udhz | {keyword}' Union All Select

Appends a new set of results to the original query [2, 5].

Comments out the rest of the original query so it doesn't cause a syntax error [1, 5]. How to Prevent It:

This is the gold standard. It treats user input as literal text, not executable code [6]. Appends a new set of results to the original query [2, 5]

Sources:[1] microsoft.com[2] portswigger.net[3] geeksforgeeks.org[4] sqlinjection.net[5] owasp.org[6] owasp.org

The best way to stop these attacks is to never "glue" user input directly into your database queries. Instead, use: It treats user input as literal text, not

Breaks out of the intended data field in a SQL query.

Are you working on or just curious about how these injection patterns work? Are you working on or just curious about

Matches the number of columns in the original table. Attackers use NULL to figure out how many columns they need to match without causing a data type error [2, 3].