Lotus Domino Servers 5.x, 4.6x, and 4.5x allows attackers to bypass the intended Reader and Author access list for a document's object via a Notes API call (NSFDbReadObject) that directly accesses the object.
http://www.kb.cert.org/vuls/id/657899
http://www.iss.net/security_center/static/10095.php
http://archives.neohapsis.com/archives/bugtraq/2001-09/0150.html
http://archives.neohapsis.com/archives/bugtraq/2001-09/0147.html