Has there been a documented exploit of this CVE on Ubuntu or on the other distros before they were patched?
I haven't had a documented packet with IPOptions arrive on any of my firewalls, the packets are typically dropped, so exploiting remotely is going to be very difficult. In theory you could use another exploit and then lateral move in some networks which don't drop them at a router level.
Here’s the real answer. It’s not as scary as the original reporters made it out to be.