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Bekijk Volledige Versie : Re: Instant Photo Gallery <= Multiple XSS



Steven M. Christey
28/04/06, 00:40
security curmudgeon mentioned:

> /portfolio.php?cat_id=[XSS]

Based on source inspection of 1.0.2, this parameter is cleansed.

line 31 of portfolio.php says:

$catId = $dbFilter->db_clean_input($_GET['cat_id'], 'integer');

which looks like it's going to do input validation as an integer.

BUT... did it do this properly?

Let's go to the definition for db_clean_input...

includes/classes/class_db_input_filter.php:

> class db_input_filter{
>
>...
>
> function db_clean_input($input, $inputType, $quoteValue=1){
>
> $this->input = $input;
> $this->inputType = $inputType;
>
>...
>
> switch($this->inputType) {
> case 'integer':
> if(ereg("^[0-9]+$", $this->input)) {
> $this->input = (int)$this->input;
> } else {
> $this->errorMsg = "Input does not match specified type (integer).";
> return false;
> }


Notice the ereg() call. It cleanses the input ONLY if it consists of
all digits. Otherwise, the function returns 'false'. The program
doesn't check if a bad value was provided, but still, this would have
the effect of setting the $catId variable to a blank value.

In February 2006, the developer also offered a "IPG Security Patch
1.0.1" which includes the portfolio.php file that is now in 1.0.2, so
maybe the portfolio.php/cat_id vector only applies to versions of
Instant Photo Gallery BEFORE 1.0.2.


portfolio_photo_popup.php / id is more clear:

>$image_id = isset($_POST['id'])?$_POST['id']:$_GET['id'];
>
>count_click($image_id);

and in includes/functions/fns_std.php:

>function count_click($image_id){
> db_connect();
> $sql = "SELECT * FROM " . PDB_PREFIX . "image_ratings WHERE id = " . $image_id;

So, we have direct SQL injection using the "id" parameter, which
produces resultant XSS if the SQL query is malformed in an
XSS-friendly fashion.

- Steve