homepage

The specific issue this is creating is that a malicious user could use this socket in a subprocess which is started from a library (ie. I'm using a .so, which calls fork/exec).
A second failure mode is starting a daemon from withing, say, a django application. Djano opens a TCP listening socket, then starts up a daemon to provide some sort of service in the background. The daemon keeps running and inherits the socket. Now you restart the django app.
It refuses to start ! Why ? Because the socket was inherited, the listening socket isn't actually closed, and this results in the socket being stuck in CLOSE_WAIT as long as the daemon is running.
It seems to me that it is almost never the case that you'd want a TCP listening socket to be preserved across exec, and not setting this flag should thus be considered a bug for 2 reasons :
1) it results in accidental disclosure of information that shouldn't be exposed in certain cases.
2) it can result in denial of service
Solution : 
update SocketServer.py :
 in the class TCPServer
 add the following 2 lines in __init__ after self.socket = socket( ...:
 flags = fcntl.fcntl(self.socket, fcntl.F_GETFD)
 fcntl.fcntl(self.socket, fcntl.F_SETFD, flags | fcntl.FD_CLOEXEC)