Rubies on the loose

Job description: Kryssen-Trupp sadly lost their admin password for the STBM. A team of ‘ruby-firmware specialists’ is needed for the extraction of the ‘password’ (flag.txt). Shell access is granted for the interview.

We get shell access to ze Schnelle Tunnelbohrmaschine Mark III Admin Interfetz. Here’s what we get upon connection:

Shellraisers and the Holy Graal

Everybody keeps talking about this new JIT. I think it is more secure, wouldn’t you agree?

compiled with: native-image -H:+ReportUnsupportedElementsAtRuntime

We get the main.clj file, which is a Clojure script! Oh boy, that’s another language I had nothing to do with (and neither had anyone from our team as far as I know). That does, however, explain the challenge title! “holy graal”, since it’s probably running on the Graal VM. Okay, but back to the topic.

Stalking at the wrong side [of query]

Howdy mate! Just login and hand out the flag, aye! You can find on h18johndoe has all you need!

What’s interesting, the h18johndoe name points to a file in an external git repository (on github): user_repo.rb

As someone once said - another weekend, another CTF! This time our team - Shellraisers - participated in the Hackover18 CTF competition and we ended up at the 5th place, w00tw00t! Gotta say we did a great job as a team and if not for the cooperation, the place could’ve not been that good ;)

There is no doubt some specifications (cough cough looking at you, Bluetooth!) are overly complicated. Not only is this a hindrance to those implementing it, but it can also cause security issues due to the many ways of bypassing the possible security mechanisms.

Today I’ve decided check out Iaitō - a frontend for the wonderful radare2. It seemed pretty neat (especially watching Hugo’s great presentation “Sweet tools o’ mine” at t2/2016) so I’ve cloned the repository, installed Qt (5.6, as suggested in the repo), installed r2 from the submodule, opened the project with Qt Creator… and stopped right there.

After running “Build” I saw an error:

r_core development package not found

If you have the same problem and did your homework, you know that’s due to the /usr/local/bin path missing in the PATH variable. This could have happened, for example, when you copied the Qt Creator.app directory over to /Applications although I haven’t done more research on that, TBH.

In order to fix that, go to the Projects tab, open Details in the Build environment section and append :/usr/local/bin to PATH (see the image below in case you have trouble finding that setting). Keep in mind that this need to be done for Debug and Release profiles separately (if I’m not mistaken; feel free to correct me otherwise).

Hopefully now it’ll be only easier ;-)

Cheers!

Why hello there! My name’s Chris (can be Kris as well) and this is another attempt of mine at creating a blog-wannabe where I could put my thoughts and ideas.

What will I post here? I’ll probably write about CTF challenges, possibly some security stuff and programming experiences. As I don’t have that much experience in the security field, for now I’ll stick with CTFs and programming. Please bear in mind that this is also an attempt to boost my writing skills (both in English and overall) so you might find some mistakes. I’d like to apologize for those in advance ;-)

See you soon!