MS anti-piracy feature trips up Office for Mac

February 8, 2002

An anti-piracy feature in Microsoft Office for the Mac contains a flaw which risks a denial of service attack. Not a very bad one, but of course not good for the reliability of MS.

A feature of the Office v. X software suite, called the Network Product Identification (PID) Checker, detects multiple copies of Office using the same product identifier running on a local network. If a duplicate PID is detected, Office shuts down.

However the software contains a flaw which means that the Network PID Checker doesn't correctly handle a particular type of malformed announcement. This will cause the process to crash, bringing the first loaded application down with it.

Microsoft categorises the vulnerability as low risk and has issued a patch... What can I say? Don't add anti-piracy features