docker-vulnerable-dvwa/dvwa/vulnerabilities/weak_id/source/low.php

<?php

$html = "";

if ($_SERVER['REQUEST_METHOD'] == "POST") {
	if (!isset ($_SESSION['last_session_id'])) {
		$_SESSION['last_session_id'] = 0;
	}
	$_SESSION['last_session_id']++;
	$cookie_value = $_SESSION['last_session_id'];
	setcookie("dvwaSession", $cookie_value);
}
?>