Advisory Name:MDaemon IMAP Denial Of Service Discovered:23rd Of March 2001 Application:Alt-N Technologies MDaemon 3.5.6 - Other versions most likely prior to this Platform:Windows 2k,95/98/NT - others unknown Severity:Denial of service from application Credit:[EMAIL PROTECTED] Vendor Status:Unknown - http://www.mdaemon.com/ Overview: Some of the commands for the IMAP server do not have proper bounds checking, enabling a user to shutdown the service remotely.It should be noted that a user account is required.The commands affected are SELECT and EXAMINE.The SELECT command selects a mailbox so that messages in it can be accessed.EXAMINE works in the same way as SELECT, however the mailbox is marked as read- only and cannot be modified. Demonstration: Connect to the service which runs on port 143 default and login with the username and pass. * OK company.mail IMAP4rev1 MDaemon 3.5.6 ready 1 LOGIN JOE PASSWORD * OK LOGIN completed 1 SELECT AAAAAAA.... Where A is more than 250 characters in length, once this is sent, MDaemon will send back the following error before closing the connection and terminating: 1 NO Mailbox does not exist A restart of the application is needed to resume the service, no other applications are affected and the operating system performs as usual. [EMAIL PROTECTED]