The Heartbleed Bug is a serious vulnerability in the popular OpenSSL cryptographic software  library. This weakness allows stealing the information protected, under normal conditions, by the SSL/TLS encryption used to secure the Internet. SSL/TLS provides communication security and privacy over the Internet for applications such as web, email, instant messaging (IM) and some virtual private networks (VPNs).

Web tool which can help you to test your service

How to solve:

sudo apt-get install openssl libssl1.0.0

Then restart all services which uses openssl