{keyword}' Union All Select Null,null,null,null,null,null,null,null From Msysaccessobjects-- Udhz May 2026

Only allow the types of characters you expect (e.g., numbers for an ID field).

This is the gold standard. It treats user input as literal text, not executable code [6]. Only allow the types of characters you expect (e

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]. Only allow the types of characters you expect (e