Can You Get Private SSL Keys Exploiting Heartbleed?

Some potentially good news on the OppenSSL Heartbleed vulnerability front, from CloudFlare:

While the vulnerability seems likely to put private key data at risk, to date there have been no verified reports of actual private keys being exposed. At CloudFlare, we received early warning of the Heartbleed vulnerability and patched our systems 12 days ago. We’ve spent much of the time running extensive tests to figure out what can be exposed via Heartbleed and, specifically, to understand if private SSL key data was at risk.

Here’s the good news: after extensive testing on our software stack, we have been unable to successfully use Heartbleed on a vulnerable server to retrieve any private key data. Note that is not the same as saying it is impossible to use Heartbleed to get private keys. We do not yet feel comfortable saying that. However, if it is possible, it is at a minimum very hard. And, we have reason to believe based on the data structures used by OpenSSL and the modified version of NGINX that we use, that it may in fact be impossible.

And now, back to changing passwords on a slew of my accounts around the web.

Update: Sadly, the answer is yes, the vulnerability does put private key data at risk.

★ Friday, 11 April 2014