The Heartbleed vulnerability is a problem that affects SSL, the technology that helps protect your information on the Internet. You use SSL when you shop online or enter sensitive information on a site that has a "lock" icon that tells you your information should be protected. This vulnerability affects some websites that use SSL making it possible for someone to access information being protected by SSL.
To know and understand more about this, you may refer to this blog below:
Don’t have heartburn over the Heartbleed Vulnerability