Bruteforcing SIP extensions with Metasploit

Hi, some time ago I published this post about VoIP information gathering with Metasploit. For a minimal pentesting process, a module capable of bruteforcing discovered extensions password is needed. So I have developed it, if you know SIPvicious suite this module provides sipcrack tool features.

Based on available SIP related modules I implemented SIP Digest Authentication algorithm and Msf::Auxiliary::AuthBrute mixin does the magic with possible user/password combinations. This picture shows an example of use in which extension 100 password is discovered (100).

Source code:

In case you use the module outside a LAN is strongly recommended to add you external IP address (option "EXTIP"), trying to avoid SIP and NAT problems.

Bye ;)

SIP INVITE attack with Metasploit

Some days ago my friend @pepeluxx wrote another post about INVITE attacks. He spoke about a @sinologic project which allows to everybody passing some security tests to SIP servers. Furthermore he also published a perl script to do the same task. So I implemented it on Metasploit because I think It could be really useful during a pentesting. It’s interesting because these attacks are really dangerous, normally, attackers try to call to expensive locations. This target numbers often have special charges and they make money with this. Here there are two well known examples: http://blog.sipvicious.org/2010/12/11-million-euro-loss-in-voip-fraud-and.html http://snapvoip.blogspot.com.es/2009/02/calls-to-cuba-and-voip-attacks.html I’m not going to deep in this vector because of being a well known (and old!!) one. Basically the attacker tries to make a call using a misconfigured PBX. This is allowed because SIP RFC says that an ...

Flooding Asterisk, Freeswitch and Kamailio with Metasploit

Hi, it has been a long time since my last post because of my new job and my final year project ("VoIP denegation of service attacks" for curious) but there is something I found during my tests with Freeswitch , Kamailio and Asterisk that I want to share. NOTE: Really, guys of Security By Default blog published us (my good friend Roi Mallo and me) two articles about how to develop modules for Metasploit framework, another two are coming. ;) During my project, among others, I developed a Metasploit module which can flood SIP protocol with common frames (INVITE, OPTIONS, REGISTER, BYE), I wrote it at Quobis (nice job ;) in order to use it for some private tests because actual software didn´t fit our needs, so we are going to probe how is the behavior of different GPL VoIP servers against this kind of attacks: - Asterisk: I think it needs no introduction, the famous softswitch/PBX software. - Freeswitch: It´s a newer soft...

SIP extension enumeration in Bluebox-ng

There are some well known SIP extension enumeration vulnerabilities in different VoIP servers, specially in Asterisk. This brute-force vector is based on the study of the authentication responses of the target server. Sometimes its replies are different in the case that the client uses a valid extension, so it's easy to discover them. This vector is normally classified as a low security risk. Moreover we're moving towards a federated SIP environment , in which the extension is the public email address of the user. But it's still important in some cases: To guide next steps during a penetration test. In example, you can use the discovered extension to reduce the number of attempts in the phase of SIP extensión brute-force. Some RCE (Remote Code Execution) exploits need a valid extension to work. After a little research, these are the known vulns: CVE-2009-3727 : It's quite old and it's practically not present in real environments. It's still not imple...

Ni ceros ni unos ...

Search This Blog