Home page logo

fulldisclosure logo Full Disclosure mailing list archives

FreePBX remote command execution, xss
From: "Martin Tschirsich" <tschirsi () rbg informatik tu-darmstadt de>
Date: Tue, 20 Mar 2012 15:21:56 +0100

Product: FreePBX
Version: 2.10.0, 2.9.0 and perhaps earlier versions
Type: Remote Command Execution, XSS
Release Date: March 14, 2012
Vendor Notification Date: Jun 12, 2011
Author: Martin Tschirsich


A remote command execution vulnerability and some XSS in current and earlier
FreePBX versions due to missing input sanitization.
FreePBX is a popular implementation (500,000 active phone systems) of
Asterisk (telephony software) based around a web-based configuration
interface and other tools. Some of these installations are on a public IP

Proof of Concept:

[HOST]/recordings/misc/callme_page.php?action=c&callmenum=[PHONENUMBER] () from

XSS (2.9.0 and perhaps other versions):

Details (RCE):

Missing input sanitization in htdocs/recordings/misc/callme_page.php:
// line 28-30:
$to         = $_REQUEST['callmenum']; // vulnerable
$msgFrom    = $_REQUEST['msgFrom'];
$new_path   = substr($path, 0, -4);     
// line 38:
$call_status = callme_startcall($to, $msgFrom, $new_path);

Missing input sanitization in htdocs/recordings/includes/callme.php:
// line 88-117:
function callme_startcall($to, $from, $new_path)
        global $astman;
        $channel        = "Local/$to () from-internal/n";  // vulnerable
        $context        = "vm-callme";
        $extension      = "s";
        $priority       = "1";
        $callerid       = "VMAIL/$from";
        /* Arguments to Originate: channel, extension, context, priority,
timeout, callerid, variable, account, application, data */
        $status = $astman->Originate($channel, $extension, $context,
$priority, NULL, $callerid, $variable, NULL, NULL, NULL, NULL);

Unofficial Patch (RCE, tested with 2.9.0):

Patch htdocs/recordings/modules/callme_page.php:
Patch htdocs/recordings/modules/voicemail.module:


The vendor has been contacted and provided with a patch several times since
Jun 12, 2011. Since no intention to address this issue was shown, I felt it
was in the best interest to disclose the vulnerability.

All information in this advisory is provided on an 'as is' basis in the hope
that it will be useful. The author not responsible for any risks or
occurrences caused by the application of this information.

Full-Disclosure - We believe in it.
Charter: http://lists.grok.org.uk/full-disclosure-charter.html
Hosted and sponsored by Secunia - http://secunia.com/

  By Date           By Thread  

Current thread:
  • FreePBX remote command execution, xss Martin Tschirsich (Mar 20)
[ Nmap | Sec Tools | Mailing Lists | Site News | About/Contact | Advertising | Privacy ]