SecRule ARGS:id1 "!^\d+$" "id:100,deny,msg='SQLi - id1 must be numeric'" Disclaimer: This article is for educational purposes and authorized security testing only.
Consider a poorly written backup script: restore.php?id1=upd&file=backup.zip inurl php id1 upd
$id = $_GET['id1']; $sql = "SELECT * FROM logs WHERE ref='upd' AND user=$id"; SecRule ARGS:id1 "