The Probert Encyclopaedia of Science & Technology

BACK DOOR

In computing, a back door is a hole in the security of a system deliberately left in place by designers or maintainers. The motivation for this is not always sinister; some operating systems, for example, come out of the box with privileged accounts intended for use by field service technicians or the vendor's maintenance programmers. Historically, back doors have often lurked in systems longer than anyone expected or planned, and a few have become widely known. The infamous RTM worm of late 1988, for example, used a back door in the BSD UNIX 'sendmail(8)' utility.
Research Back door