A fix is now available for a serious Open SSL flaw known as Heartbleed. The vulnerability, covered in CVE-2014-0160, affects OpenSSL 1.0.1 through 1.0.1f with two exceptions: OpenSSL 1.0.0 branch and 0.9.8.
OpenSSL describes the flaw -- and fix -- in this advisory:
OpenSSL Security Advisory [07 Apr 2014] ======================================== TLS heartbeat read overrun (CVE-2014-0160) ========================================== 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. Only 1.0.1 and 1.0.2-beta releases of OpenSSL are affected including 1.0.1f and 1.0.2-beta1. Thanks for Neel Mehta of Google Security for discovering this bug and to Adam Langley <email@example.com> and Bodo Moeller <firstname.lastname@example.org> for preparing the fix. Affected users should upgrade to OpenSSL 1.0.1g. Users unable to immediately upgrade can alternatively recompile OpenSSL with -DOPENSSL_NO_HEARTBEATS. 1.0.2 will be fixed in 1.0.2-beta2.
A lot of publicity has surrounded this vulnerability, some of it downright alarming. Akamai CSIRT Director Michael Smith said the alarm isn't necessary, especially since a fix has been released.
"Keep calm and crypto on," he said.
That said, those affected should update to the latest version now.