Stack-based buffer overflow in Pegasus Mail (PMail) 4.41 and possibly 4.51 allows remote POP3 servers to cause a denial of service (application crash) or possibly execute arbitrary code via a long error message.
https://exchange.xforce.ibmcloud.com/vulnerabilities/53933
http://www.vupen.com/english/advisories/2009/3026
http://www.securityfocus.com/archive/1/507377/100/0/threaded