Technical information

Automated Attendant
Issue 7 June 2001
3-3
Automated Attendant
Automated attendant systems direct calls to pre-designated stations by offering
callers a menu of available options. Automated attendant devices are connected
to a port on the main system and provide the necessary signaling to the switch
when a call is being transferred. When hackers connect to an automated
attendant system, they try to find a menu choice (even one that is unannounced)
that leads to an outside facility.
Hackers also may try entering a portion of the toll number they are trying to call to
see if the automated attendant system passes the digits directly to the switch. To
do this, the hacker matches the length of a valid extension number by dialing only
a portion of the long distance telephone number. For example, if extension
numbers are four digits long, the hacker enters the first four digits of the long
distance number. After the automated attendant sends those numbers to the
switch and disconnects from the call, the hacker provides the switch with the
remaining digits of the number.
Many voice messaging systems incorporate automated attendant features. The
security risks associated with automated attendant systems are common to voice
messaging systems as well. Refer to Chapter 7 for more information on securing
automated attendant systems.
Other Port Security Risks
Many of the security risks from voice mail, Remote Access, and automated
attendant arise from allowing incoming callers to access outside facilities.
However, there are other endpoints within your system that should also be denied
to incoming callers. Many of these endpoints can be dialed as internal calls within
the system, and can be reached from either voice mail, auto attendant, or Remote
Access.
For example, the NETCON (Network Control) data channels provide internal
access to the system management capabilities of the system and can be reached
on a call transfer from an AUDIX Voice Mail System if not protected by appropriate
restrictions. [See ‘‘Increasing Product Access (Port) Security’’ on page 3-6.] Any
features or endpoints that can be dialed, but are to be denied to incoming callers,
should be placed in restriction groups that cannot be reached from the incoming
facility or from endpoints that could transfer a call.
Sophisticated modems being used today, if not protected, offer incoming callers
the ability to remotely request the modem to flash switch-hook, returning second
dial tone to the incoming caller. Modem pool ports need to be appropriately
protected or otherwise denied access to second (recall) dial tone. Outgoing-only
modem pools are at risk if they can be dialed as extensions from any of the
remote access or voice mail ports as in the example above. (See ‘‘Recall
Signaling (Switchhook Flash)’’ on page 4-19.)