Race condition in the FTPHandler class in ftpserver.py in pyftpdlib before 0.5.2 allows remote attackers to cause a denial of service (daemon outage) by establishing and then immediately closing a TCP connection, leading to the accept function having an unexpected value of None for the address, or an ECONNABORTED, EAGAIN, or EWOULDBLOCK error, a related issue to CVE-2010-3492.
https://bugs.launchpad.net/zodb/+bug/135108
http://www.openwall.com/lists/oss-security/2010/09/24/3
http://www.openwall.com/lists/oss-security/2010/09/22/3
http://www.openwall.com/lists/oss-security/2010/09/11/2
http://www.openwall.com/lists/oss-security/2010/09/09/6
http://code.google.com/p/pyftpdlib/source/detail?r=556
http://code.google.com/p/pyftpdlib/source/browse/trunk/HISTORY
http://code.google.com/p/pyftpdlib/issues/detail?id=105