HTB Irked

Lessons Learned

  1. Debian doesn't have the command sudo if root password is set.
  2. steghide extract -sf irked.jpg (steghide exists).
  3. TEST OUT ALL SUIDS THAT DON'T END UP IN DEFAULT.
  4. HexChat is an IRC client.

Walkthrough

I first do an aggressive nmap scan. I find a web server with a few IRC ports open.

I connect via netcat on port 6697, 8067, and 65534. I see some activity going on. The other port, 40542 is not responding. From using IRC in the past, I know I need an IRC client. I download HexChat to use.

I see that the banner version is displaying when I connect. It says Unreal3.2.8.1. I try out some exploits and find this one works the best: https://github.com/Ranger11Danger/UnrealIRCd-3.2.8.1-Backdoor

Open up exploit.py and change the lines to your IP Address and port

Be careful with the shell. If it gets stuck, you will need to restart the box. A trick of mine is to have the shell open up another shell with OpenBSD Netcat. If I quit the second shell, the first shell will go back to normal.

This part I had to look up. I guess you would know to use steghide if you encountered it before. The image contains a pass.txt and with the .backup password, you can open it.

I return to my shell tab and input the password for djmardov.

I tried a few different things to Priv Esc. I was confused on why sudo wasn't on the box. I found a few answers that said something along the lines of this: https://unix.stackexchange.com/questions/106529/why-is-sudo-not-installed-by-default-in-debian. All of my sudo jutsus were trashed. LinPeas wasn't picking up anything. Neither was LinEnum. I ran Lin-Local-Suggester and found DirtyC0w was highly possible. I tried 3 dirtyc0w exploits and they failed. I noticed viewuser in suid and that was the way to escalate.

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