User`s guide

6-84 Setting up Meridian Mail security
Overview
Standard 1.0 System Administration Guide January 1998
Overview
Description:
DISA
Direct Inward System Access (DISA) provides a convenient
means by which employees, when they are offsite, can place
calls to internal extensions, and to private and public network
locations by accessing your company’s switching system.
How DISA is abused
The type of unauthorized access associated with this feature
begins when perpetrators find the telephone number associated
with DISA. In most DISA intrusion cases, hackers use PC-
based programs to obtain valid DISA DNs, and security and
authorization codes. Once a PC program finds a valid DISA
telephone number, the PC inputs codes, redials the telephone
number repeatedly, and stores the valid codes. Hackers then sell
the numbers and codes they obtain illegally to third parties who
then use this information for their own “business purposes.”
In this section
In this section, you will learn how to effectively manage and
monitor the Meridian 1 DISA feature.