A server listens for TCP connections on TCP port 17. Once a connection is established a short message is sent out the connection (and any data received is thrown away). The service closes the connection after sending the quote.
Another quote of the day service is defined as a datagram based application on UDP. A server listens for UDP datagrams on UDP port 17. When a datagram is received, an answering datagram is sent containing a quote (the data in the received datagram is ignored).
Oracle released an emergency software update today to fix a security vulnerability in its Java software that could allow attackers to break into computers.
The update, which is available on Oracle's Web site, fixes a critical vulnerability in Oracle's Java 7 that could allow a remote, unauthenticated attacker to execute arbitrary code. The attack can be induced if someone visits a Web site that's been set up with malicious code to take advantage of the hole.