The venerable “secure” network protocol Secure Sockets Layer (SSL) v3 has met its end. SSL has co-existed on the Internet alongside its presumed successor TLS for many years, even though experts have long warned of its shortcomings. A recent rash of high-profile incidents, however, including the famous POODLE exploit, have finally caused the Internet Engineering Task Force (IETF) to take action. Request for Comment (RFC) 7568 “Deprecating Secure Sockets Layer Version 3.0” officially states the requirement that SSLv3 should not be supported.

The RFC is unusually blunt, with its all-cap stipulation that “SSLv3 MUST NOT be used.” Although most systems today support the safer TLS, many provide fallback support for SSLv3 if an SSL connection is requested. Attackers have perfected the technique of requesting an SSL connection then use one of the many exploits associated with SSL. RFC 7568 states that “Any party receiving a Hello message with the version set to {3,00} MUST respond with a ‘protocol_version’ alert message and close the connection.”

Many OS and application vendors have already turned off support for SSLv3 through patches and security updates.