Extensionis a hard-rated Linux machine from Hack The Box. This is a very interesting machine that’s beautifully made, the attack surface is slim and there are a lot of rabbit holes to waste time on. Looking back on each vulnerability they all seem easy, but finding them all took a lot of time and effort - I think I spent around 25 hours in total on this box. Even though it took a lot of time, I really enjoyed it - especially the XSS part as it showcases the real dangers of XSS. I did learn a lot from this machine and I deeply recommend it to anyone!