The default configuration of McAfee VirusScan 4.5 does not quote the ImagePath variable, which improperly sets the search path and allows local users to place a Trojan horse "common.exe" program in the C:\Program Files directory.
https://euvd.enisa.europa.eu/vulnerability/EUVD-2000-1113
http://www.securityfocus.com/bid/1920
http://archives.neohapsis.com/archives/ntbugtraq/2000-q4/0073.html