The bug uncovered by Google Security has been dubbed "Heartbleed" makes it possible to fool OpenSSL systems into revealing part of the data in their system memories. Security expert Graham Cluley said that the bug could reveal SSL keys. This would allow hackers to do even more damage, without leaving a trace.
Elastica's CTO Dr Zulfikar Ramzan has posted a detailed walkthrough on his company's website. He stresses that the flaw is not inherent in the SSL/TLS protocol itself but in the specific OpenSSL implementation.
There is a workthrough site. Admins need to update to OpenSSL 1.0.1g immediately, and regenerate private keys. If an update to the latest version of OpenSSL isn’t possible it advises developers to recompile OpenSSL with the compile time option OPENSSL_NO_HEARTBEATS.
It is not as if this bug has not been known about for a while. It has been in OpenSSL since December 2011 though it was only publicly announced yesterday. So far, there is no indication if it has been exploited in the wild; Heartbleed leaves no trace in the server’s logs so it’s hard to know if a system has been compromised.