Today a new vulnerability was announced in OpenSSL 1.0.1 that allows an attacker to reveal up to 64kB of memory to a connected client or server (CVE-2014-0160). We fixed this vulnerability last week before it was made public. All sites that use CloudFlare for SSL have received this fix and are automatically protected.
OpenSSL is the core cryptographic library CloudFlare uses for SSL/TLS connections. If your site is on CloudFlare, every connection made to the HTTPS version of your site goes through this library. As one of the largest deployments of OpenSSL on the Internet today, CloudFlare has a responsibility to be vigilant about fixing these types of bugs before they go public and attackers start exploiting them and putting our customers at risk.
We encourage everyone else running a server that uses OpenSSL to upgrade to version 1.0.1g to be protected from this vulnerability. For previous versions of OpenSSL, re-compiling with the OPENSSL_NO_HEARTBEATS flag enabled will protect against this vulnerability. OpenSSL 1.0.2 will be fixed in 1.0.2-beta2.
This bug fix is a successful example of what is called responsible disclosure. Instead of disclosing the vulnerability to the public right away, the people notified of the problem tracked down the appropriate stakeholders and gave them a chance to fix the vulnerability before it went public. This model helps keep the Internet safe. A big thank you goes out to our partners for disclosing this vulnerability to us in a safe, transparent, and responsible manner. We will announce more about our responsible disclosure policy shortly.
Just another friendly reminder that CloudFlare is on top of things and making sure your sites stay as safe as possible.