OpenSSL heartbeat bug patch (CVE-2014-0160):

https://github.com/openssl/openssl/commit/731f431497f463f3a2...

A missing bounds check in the handling of the TLS heartbeat extension can be used to reveal up to 64k of memory to a connected client or server.

Previous discussion: https://news.ycombinator.com/item?id=7557825