Instruction manual

Administration / maintenance access

Issue 9 May 2003

4-7

Another area that may be vulnerable to toll fraud is the System 75 and the

DEFINITY ECS, DEFINITY G1 and G3 (except G3r) NETCON data channel —

the internal extension number that can be used for administration and

maintenance access. If the NETCON data channel is not restricted, a hacker can

do a valid transfer from the voice mail port (or other ports in the system) to the

network extension, get dial tone, and connect to and log into the administrative

port, bypassing any port protection device, such as an RPSD. In a modem pool or

NETCON modem installation, this would permit a hacker to transfer to a NETCON

extension, get data tone, and get a login prompt. In a modem pool installation, this

would also permit the hacker to transfer out to make toll calls.

Use COR-to-COR restrictions to restrict stations from calling the NETCON so that

only CORs allowed to access the maintenance port are able to do so. For

example, if voice mail extensions have a COR of 9, and extensions assigned to

NETCON channels have a COR of 2, ensure that COR 9 does not have access to

COR 2. Anyone not authorized to use the NETCON channel should not be able to

access it.

NOTE:

To determine how the NETCON channels have been assigned, use the list

data-module

command. The output from this command identifies the

modules in your system. If NETCON extensions are administered, they will

be listed as NETCON, along with the four 3- or 4-digit extension numbers

associated with the data channel(s).

NOTE:

NETCON extensions may also be contained in a hunt group. If list

data-module

does not list the NETCON extensions, use list hunt-group to

see if the NETCON data channels are in a hunt group.

NOTE:

For verification purposes, you may also enter list data-module

, if you think you know the extension that is associated with the

NETCON data channel. This command will list the COR, COS, Tenant

Number, and name of the data module (for example, NETCON, TDM)

associated with the extension you entered.

In addition, the modem port used for voice mail maintenance or administrative

access is often a switch extension. It should be restricted in the same manner as

the NETCON channel.