Security experts have discovered a critical vulnerability in OpenSSH which affects versions from 5.4 to 7.1 and it allows attackers to steal encrypted private keys.
A new OpenSSH version has been released to patch this vulnerability, so it is strongly recommended to update to this new release. Another option is to deactivate the vulnerable code adding "UseRoaming no” option in ssh_config file.
The affected versions have experimental support to restart SSH connections and the client code was activated by default. This configuration allows malicious servers to leak memory to the server, including user's private keys.
OpenSSH is a Secure Shell (SSH) implementation, a protocol which helps to secure network communications via the encryption of network traffic over multiple authentication methods and by providing secure tunneling capabilities. It can be implemented to different Linux-based OS, such as Ubuntu and Mac OS X.