I'm no php programmer, only site admin, I've recently adopted a site with web panel that causes sql injection when trying to post html code in TinyMCE, containing apostrophe.
Problematic html code;
img onmouseover="this.src='layout/gfx/wiecej1.png'
php code;
$edytuj = $_POST['edytuj'];
sql query;
if($edytuj) {
$podstrony_id = $_POST['id'];
$podstrony_id_kategorie = $_POST['id_kategorie'];
$podstrony_id_moduly = $_POST['id_moduly'];
$podstrony_tytul = $_POST['tytul'];
$podstrony_szablon = $_POST['szablon'];
$podstrony_tresc = $_POST['tresc'];
$podstrony_aktywnosc = $_POST['aktywnosc'];
$zapytanie = "UPDATE $tab_podstrony SET id_kategorie='$podstrony_id_kategorie', id_moduly='$podstrony_id_moduly', tytul='$podstrony_tytul', szablon='$podstrony_szablon', tresc='$podstron$
$wynik = mysql_query($zapytanie);
Site uses php-cgi-5.4.39 and mysql-5.5 I don't have access to previous environment (where this panel worked fine), so I can't find out if it's configuration or code problem.