A security vulnerability in the OpenSSL cryptographic software forced Mojang to shut down its servers temporarily Tuesday and recommend to all Minecraft and Scrolls players that they immediately change the passwords associated with their accounts.
"As soon as we realized the severity of the exploit we decided to shut down all of our systems until a fix was available," Mojang's Kristoffer Jelbring wrote on the developer's website. "This is why you were unable to log in yesterday. We then made sure that all of our services that use SSL no longer had this vulnerability before bringing them back online. We also updated all of our SSL certificates."
Jelbring went on to advise players to change the passwords to both their Minecraft account and Mojang account as well as passwords for any other services that you may use that are affected by the vulnerability.
The Legacy Launcher for Minecraft and the login.minecraft.net service have been discontinued as a result of the exploit being made known. Minecraft players are now required to use the launcher that comes with version 1.6 or later.
"The current launcher lets you play older versions of Minecraft as well so you can still play on your pre-1.6 servers," Jelbring assured.