Hackers can take control of your server if you expose Redis to public access without proper authentication. By connecting to a Redis server without authentication a malicious user can eventually take control of the user running the Redis server (usually root). For more details read this blog post explaining the attack vector.
How do we test it:This page tests a connection to the Redis server with no authentication credentials. If this is successful the server is not safe. Otherwise, the server is considered "safe" for this type of attack.
How to make your server secure:* If you have Redis bound to the `0.0.0.0` IP, you need to protect it with a firewall. * Require a password to authenticate on Redis.