Rit Research Labs The Bat! 1.51 for Windows allows a remote attacker to cause a denial of service by sending an email to a user's account containing a carriage return <CR> that is not followed by a line feed <LF>.
Rit Research Labs The Bat! 1.0.11 through 2.0 creates new accounts with insecure ACLs, which allows local users to read other users' email messages.