This line in your output shows that the "backing file" exploit was attempted:
Could not open '/etc/nova/nova.conf': Permission denied
Luckily it didn't succeed due to a permissions issue, but it might succeed for other files in your installation, so you should definitely upgrade/patch it.
@Guiseppe at comment #165:
This line in your output shows that the "backing file" exploit was attempted:
Could not open '/etc/nova/ nova.conf' : Permission denied
Luckily it didn't succeed due to a permissions issue, but it might succeed for other files in your installation, so you should definitely upgrade/patch it.