The Heartbleed bug is a vulnerability in OpenSSL's TLS implementation. The CVE ID for this issue is CVE-2014-0160

The Heartbleed vulnerability allows stealing the information which is protected by SSL/TLS encryption, as well as potential disclosure of private keys.

Any application using OpenSSL for its TLS implementation is potentially vulnerable, which means there is large variety of vulnerable applications such as Web browsers, Email clients and Instant Messaging softare.

See http://heartbleed.com or CVE-2014-0160 for more information.