A serious vulnerability has been discovered in the OpenSSL cryptographic software library which allows an attacker to steal information that would normally be protected by SSL/TLS encryption. This vulnerability allows anyone to compromise and steal data that is normally protected by this protocol, which can lead to further attacks and the compromise of IT systems that are breached.
There are many popular firewalls and systems that are exposed on the Internet that use this protocol, which makes this vulnerability a serious threat. Many common Linux based operating systems are vulnerable, and the vendors have released patches to fix this issue. It is recommended that firewalls, servers and appliances that use OpenSSL be patched immediately.
For more information on this threat and some answers to common questions, read this – http://heartbleed.com/
To test your system for this vulnerability, go to this site – http://filippo.io/Heartbleed/