Python: SMTP proxy RFC 2821 module DoS (uncaught exception) (Issue #9129)

Multiple race conditions in smtpd.py in the smtpd module in Python 2.6, 2.7, 3.1, and 3.2 alpha allow 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 return value of None...