On April 7, 2014 a severe vulnerability called “Heartbleed” was announced. Heartbleed is a vulnerability within the OpenSSL 1.0.1 series software that is described in the NIST CVE-2014-0160 announcement. In short, this vulnerability allows hackers access to portions of a vulnerable system’s memory, leading to the potential exposure of passwords, sensitive data, and certificate private keys on affected systems. Heartbleed accomplishes this by exploiting a weakness in the “TLS Heartbeat Extension,” exposing server memory. Even worse, this heartbeat attack can be repeated without the awareness of the victim, and each iteration reveals another 64k snapshot of memory to the attacker. This very serious vulnerability exposes the most sensitive data of affected systems.
The good news: the vulnerability has a patch. However, the widespread adoption of the OpenSSL 1.0.1 series software, coupled with the two years that this vulnerability has existed, means that the risks attributable to Heartbleed are enormous. Current estimates predict that over 500,000 systems may be vulnerable. Specifically, the Heartbleed vulnerability affects those systems that use OpenSSL 1.0.1 (a-f). Unfortunately, since this software is so widely implemented, many popular OS platforms are affected and thus vulnerable. I would suggest visiting the CERT Web Site for a more list of affected platforms. It is worth mentioning that this is a developing story, and as such, the list of affected platforms is likely to change.