Multiple stack-based buffer overflows in CMailCOM.dll in CMailServer 5.4.6 allow remote attackers to execute arbitrary code via a long argument to the (1) CreateUserPath, (2) Logout, (3) DeleteMailByUID, (4) MoveToInbox, (5) MoveToFolder, (6) DeleteMailEx, (7) GetMailDataEx, (8) SetReplySign, (9) SetForwardSign, and (10) SetReadSign methods, which are not properly handled by (a) the POP3 Class ActiveX control (CMailCom.POP3); or a long argument to the (11) AddAttach, (12) SetSubject, (13) SetBcc, (14) SetBody, (15) SetCc, (16) SetFrom, (17) SetTo, and (18) SetFromUID methods, which are not properly handled by the Class ActiveX control (CMailCOM.SMTP), as demonstrated via the indexOfMail parameter to mwmail.asp.