[VoiceOps] looking for advice on international fraud that took place via an Edgemarc 200EW with FXO line installed

Matt Yaklin myaklin at g4.net
Fri Nov 1 13:01:46 EDT 2013


Since radius server authentication is enabled any attempt
to login as rouser would go via that method. My radius server
does not have a rouser.

Only when the Edgemarc cannot reach the radius server or when
the radius secret password is incorrect would it fall back to
local auth.

But yes we changed it during the initial config. It is not
a very strong password though since we are limited to 6-8
characters by the software. I just think the attacker never
had a chance to use it since the device has been online
and reachable via our network.

matt at g4.net

On Fri, 1 Nov 2013, Keith Croxford wrote:

> Do you have the 'read only' user password changed on the Edgemarc? I've seen interesting problems occur when the 'read
> only' account is vulnerable.
> Keith
> On Fri, Nov 1, 2013 at 9:30 AM, Matt Yaklin <myaklin at g4.net> wrote:
>       Hi all,
>       I had some toll fraud to Grenada last night which we stopped as soon
>       as we became aware of it. Example numbers being dialed were:
>       1-473-405-0085
>       1-473-405-0084
>       1-473-405-0088
>       Normally I can track down how it happened to figure out who was at fault.
>       But this time I am having a hard time.
>       The customer has two types of service from us. Yealink phones connected
>       to our Broadsoft system with an Edgemarc 200EW installed at the customer
>       premise. They also have some POTS line with us for faxing. One of those
>       POTS lines is connected to the Edgemarc 200EW via the built in FXO port
>       for "Survivability". Meaning if the WAN ethernet port on the Edgemarc has
>       a failure they can at least have one line to dial out on in case of an
>       emergency. That is about the only time it would ever be used except for
>       faxing.
>       The toll fraud CPN just happens to be that POTS line connected to the
>       Edgemarc. That POTS line is also connected to a very basic fax machine.
>       In the Edgemarc for that FXO port two stage dialing is disabled in
>       both directions. We had incoming calls on the FXO line being forward to a
>       Yealink phone but that would never function properly due to the customer
>       having a fax line picking up first. Just leftover config during the
>       install where we made an assumption the customer might want it.
>       The Yealink phones are behind the Edgemarc (NAT) and not reachable via the
>       internet. The Edgemarc is using radius for user auth and has strong
>       passwords set. I cannot find any config in Broadsoft where a user
>       had call forwarding setup or whatever that would cause this. I cannot find
>       any settings in the Edgemarc that would allow this to take place. As in
>       a config mistake.
>       The Edgemarc is running code Version 11.6.19.
>       The Yealink phones are also up2date with the newest code from the vendor's
>       website.
>       I do not think this fraud was done on site via physical means. It is
>       a school and I just cannot picture a student or faculty having a need
>       to call Grenada.
>       The Edgemarc does have port 5060 open to the world but it is just a ?proxy?
>       I was under the impression that one cannot brute force an account on a
>       proxy device that has no config as such like an asterisk box would. You
>       would be basically brute forcing against Broadsoft in that case?
>       Either way I am still digging into things but I thought by sending this
>       email someone might have some advice to clue me into something I am
>       missing when it comes to Edgemarc and FXO security.
>       Thanks,
>       matt at g4.net
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