Technical information

DEFINITY ECS, DEFINITY Communications Systems,
System 75, and System 85
Issue 7 June 2001
6-33
Security Measures
Design applications with toll fraud in mind.
 Make sure the application verifies that long distance numbers are not being
requested, or that only permitted numbers are requested. The Transfer Call
and Call Bridge capabilities of Script Builder, and the “tic” instruction at the
Transaction State Machine (TSM) script level provide network access. If
the ASAI package is loaded, additional TSM instructions and libraries
provide access using the ASAI facility. In addition, a poorly designed
Prompt and Collect action for transfer could let the caller enter any number
for an outside access number.
 If numbers are contained in a database where anyone with database
access can change them, or if they are entered by the caller, fraud is
possible. Build the numbers into the application, or have the application
control them to minimize the possibility of toll fraud.
 The VIS Feature Test (feature_tst) package contains application programs
that can be assigned to channels to test system components that allow any
4-digit number to be dialed, such as transfer and call bridging. The
application should not be assigned to a channel, or the package should not
be loaded except when these tests are being used.
 Anyone with access to application code can hide logic in it that provides
network access and is triggered under specific circumstances. Make sure
that only trusted individuals can access application code.
 An application can be audited using Automatic Number Identification (ANI)
capabilities through PRI and ASAI (or normal call data tools) to set up local
database tables to collect numbers. If a significant number of repeat
inbound calls are identified, an administrator can be notified using the
Netview package, UNIX, or ARU, or an application can be spawned to call
someone to alert the administrator about the calls.
Protect local and remote access.
 Restrict login access to trusted individuals with a need to maintain or
administer the system.
 Restrict remote login access.
 Use the administrative interface and its security classes for logins. Certain
capabilities are restricted for particular classes. For example, the
Operations class cannot modify applications.
 Make sure when you use a modem that it is administered properly to
prevent access by outside users. Make sure the phone is disconnected
from the modem when the modem is not in use, or use the RPSD lock.
 Use standard UNIX tools to monitor login statistics.