Dial Back isn't always secure

John M Sellens jmsellens at watmath.UUCP
Fri Mar 1 18:04:05 AEST 1985


Dave Emery's article is very informative and raises a number of good points.

If I may add my 2 cents worth:

Perhaps part/all (although "all" would be too much to hope for) of the risk
associated with the dial-out line can be alleviated in one of two ways.
1 - always use a local line to call out.  By this I mean an extension line
    on your internal PBX, and dial 9 for an outside line.  The specific
    outside line would be harder (hopefully) for the cracker to determine,
    and perhaps PBX's are smarter at avoiding such line collisions.
2 - Use call forwarding on the outgoing line.  Have all incoming calls on
    the outgoing line forwarded to the incoming line.  This has the
    advantage that even small organizations can use it and it's simple.

Thanks Dave!

John



More information about the Comp.unix.wizards mailing list