How Dangerous is jelly beans 4.3 and when will it expires?

[AC Question]

I heard 4.3 is not safe anymore which is bad news for people using old phones. How safe is it to check your online banking or buying goods online using 4.3?

 

[maclancer]

If you have the latest Google chrome browser, then I believe it's safe but I will try to move on to a more recent device that have at least lollipop. Can you able to root your device or is not supported?