[yokai_old]

3.2.xx < 3.8.10( the first kernel with the update built-in ).

There are patches to be had to resolve that exploit, but servers aren't notorious for updating regularly.

You a high nigga, that colonel is June 2013, aka immune; if he got lucky and that date is just from the build (doubt it), semtex won't pop it; you can try sorbo's exploit or brad's (grab the symbols and either hardcode them into the exploits or w/e - it's easy but good luck lmao). @OP, "I do agree that it's a pretty up-to-date kernel" - please don't talk when you have no idea what you're saying.

Go read up on format string exploitation, and unfuck the death-star.c exploit (assuming the output of sudo -V is 1.8.3 or lower?). Also check if pkexec version = under 102 or not. You can also try to fuck with mtab if fusermount is set uid. I'm going to say your best bet is to check for vuln crons and or grep for credentials that may have been reused.