http://www.theregister.co.uk/2015/12/21/security_code_to_backdoor_juniper_firewalls_revealed_in_firmware/
I'm not sure on the scope / risk of this. May be it's only a risk if you allow SSH / Telnet from unsecure networks?
The backdoor also lets you decrypt the data i believe.
Dlots is correct.
It also means that, after applying the patches, some people may not be able to VPN in... I am awkwardly hanging as my VPN keeps going to a "waiting to connect" state. I may even have to call the helpdesk.