The IMAP server in IMail Server 8.20 in Ipswitch Collaboration Suite (ICS) before 2.02 allows remote attackers to cause a denial of service (crash) via a long argument to the LIST command, which causes IMail Server to reference invalid memory.
http://www.vupen.com/english/advisories/2005/2782
http://www.securityfocus.com/bid/15753
http://www.idefense.com/application/poi/display?id=347&type=vulnerabilities