Heartbleed (“bleeding heart”) is a flaw affecting the Open SSL software, widely used on the internet program that encrypt communications. As soon as you connect to a site, you exchange information with a server. Open SSL is supposed to guarantee the confidentiality of such contacts, especially when you connect to a banking site, for example, or when you enter a password.
These secure exchanges are symbolized by a small green padlock next to the address bar of your browser.
After revelation of the vulnerability globally, an update was deployed on the interface.