Linux detailed Enumeration – Commands

This blog is largely forked from the g0tmi1k’s blog https://blog.g0tmi1k.com/2011/08/basic-linux-privilege-escalation/

Thanks, G0tm1lk for your amazing contribution to the industry.

Operating System

What’s the distribution type? What version?

cat /etc/issue cat /etc/*-release cat /etc/lsb-release # Debian based cat /etc/redhat-release # Redhat based

What’s the kernel version? Is it 64-bit?

cat /proc/version uname -a uname -mrs rpm -q kernel dmesg | grep Linux ls /boot | grep vmlinuz-

What can be learned from the environmental variables?

cat /etc/profile cat /etc/bashrc cat ~/.bash_profile cat ~/.bashrc cat ~/.bash_logout env set

Is there a printer?

lpstat -a

Applications & Services

What services are running? Which service has which user privilege?

ps aux ps -ef top cat /etc/services

Which service(s) are been running by root? Of these services, which are vulnerable – it’s worth a double check!

ps aux | grep root ps -ef | grep root

What applications are installed? What version are they? Are they currently running?

ls -alh /usr/bin/ ls -alh /sbin/ dpkg -l rpm -qa ls -alh /var/cache/apt/archivesO ls -alh /var/cache/yum/

Any of the service(s) settings misconfigured? Are any (vulnerable) plugins attached?

cat /etc/syslog.conf cat /etc/chttp.conf cat /etc/lighttpd.conf cat /etc/cups/cupsd.conf cat /etc/inetd.conf cat /etc/apache2/apache2.conf cat /etc/my.conf cat /etc/httpd/conf/httpd.conf cat /opt/lampp/etc/httpd.conf ls -aRl /etc/ | awk '$1 ~ /^.*r.*/

What jobs are scheduled?

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

Any plain text usernames and/or passwords?

grep -i user [filename] grep -i pass [filename] grep -C 5 "password" [filename] find . -name "*.php" -print0 | xargs -0 grep -i -n "var $password" # Joomla

Communications & Networking

What NIC(s) does the system have? Is it connected to another network?

/sbin/ifconfig -a cat /etc/network/interfaces cat /etc/sysconfig/network

What are the network configuration settings? What can you find out about this network? DHCP server? DNS server? Gateway?

cat /etc/resolv.conf cat /etc/sysconfig/network cat /etc/networks iptables -L hostname dnsdomainname

What other users & hosts are communicating with the system?

lsof -i lsof -i :80 grep 80 /etc/services netstat -antup netstat -antpx netstat -tulpn chkconfig --list chkconfig --list | grep 3:on last w

Whats cached? IP and/or MAC addresses

arp -e route /sbin/route -nee

Is packet sniffing possible? What can be seen? Listen to live traffic

tcpdump tcp dst 192.168.1.7 80 and tcp dst 10.5.5.252 21

Note: tcpdump tcp dst [ip] [port] and tcp dst [ip] [port]

Confidential Information & Users

Who are you? Who is logged in? Who has been logged in? Who else is there? Who can do what?

id who w last cat /etc/passwd | cut -d: -f1 # List of users grep -v -E "^#" /etc/passwd | awk -F: '$3 == 0 { print $1}' # List of super users awk -F: '($3 == "0") {print}' /etc/passwd # List of super users cat /etc/sudoers sudo -l

What sensitive files can be found?

cat /etc/passwd cat /etc/group cat /etc/shadow ls -alh /var/mail/

Anything “interesting” in the home directories? If it’s possible to access

ls -ahlR /root/ ls -ahlR /home/

Are there any passwords in; scripts, databases, configuration files or log files? Default paths and locations for passwords

cat /var/apache2/config.inc cat /var/lib/mysql/mysql/user.MYD cat /root/anaconda-ks.cfg

What has the user is doing? Is there any password in plain text? What have they been editing?

cat ~/.bash_history cat ~/.nano_history cat ~/.atftp_history cat ~/.mysql_history cat ~/.php_history

What user information can be found?

cat ~/.bashrc cat ~/.profile cat /var/mail/root cat /var/spool/mail/root

Can private-key information be found?

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

File Systems

Which configuration files can be written in /etc/? Able to reconfigure a service?

ls -aRl /etc/ | awk '$1 ~ /^.*w.*/' 2>/dev/null # Anyone ls -aRl /etc/ | awk '$1 ~ /^..w/' 2>/dev/null # Owner ls -aRl /etc/ | awk '$1 ~ /^.....w/' 2>/dev/null # Group ls -aRl /etc/ | awk '$1 ~ /w.$/' 2>/dev/null # Other find /etc/ -readable -type f 2>/dev/null # Anyone find /etc/ -readable -type f -maxdepth 1 2>/dev/null # Anyone

What can be found in /var/?

ls -alh /var/log ls -alh /var/mail ls -alh /var/spool ls -alh /var/spool/lpd ls -alh /var/lib/pgsql ls -alh /var/lib/mysql cat /var/lib/dhcp3/dhclient.leases

Any settings/files (hidden) on the website? Any settings file with database information?

ls -alhR /var/www/ ls -alhR /srv/www/htdocs/ ls -alhR /usr/local/www/apache22/data/ ls -alhR /opt/lampp/htdocs/ ls -alhR /var/www/html/

Is there anything in the log file(s) (Could help with “Local File Includes”!)

cat /etc/httpd/logs/access_log cat /etc/httpd/logs/access.log cat /etc/httpd/logs/error_log cat /etc/httpd/logs/error.log cat /var/log/apache2/access_log cat /var/log/apache2/access.log cat /var/log/apache2/error_log cat /var/log/apache2/error.log cat /var/log/apache/access_log cat /var/log/apache/access.log cat /var/log/auth.log cat /var/log/chttp.log cat /var/log/cups/error_log cat /var/log/dpkg.log cat /var/log/faillog cat /var/log/httpd/access_log cat /var/log/httpd/access.log cat /var/log/httpd/error_log cat /var/log/httpd/error.log cat /var/log/lastlog cat /var/log/lighttpd/access.log cat /var/log/lighttpd/error.log cat /var/log/lighttpd/lighttpd.access.log cat /var/log/lighttpd/lighttpd.error.log cat /var/log/messages cat /var/log/secure cat /var/log/syslog cat /var/log/wtmp cat /var/log/xferlog cat /var/log/yum.log cat /var/run/utmp cat /var/webmin/miniserv.log cat /var/www/logs/access_log cat /var/www/logs/access.log ls -alh /var/lib/dhcp3/ ls -alh /var/log/postgresql/ ls -alh /var/log/proftpd/ ls -alh /var/log/samba/ Note: auth.log, boot, btmp, daemon.log, debug, dmesg, kern.log, mail.info, mail.log, mail.warn, messages, syslog, udev, wtmp

How are file-systems mounted?

mount df -h

Are there any unmounted file-systems?

cat /etc/fstab

What “Advanced Linux File Permissions” are used? Sticky bits, SUID & GUID

find / -perm -1000 -type d 2>/dev/null # Sticky bit - Only the owner of the directory or the owner of a file can delete or rename here. find / -perm -g=s -type f 2>/dev/null # SGID (chmod 2000) - run as the group, not the user who started it. find / -perm -u=s -type f 2>/dev/null # SUID (chmod 4000) - run as the owner, not the user who started it. find / -perm -g=s -o -perm -u=s -type f 2>/dev/null # SGID or SUID for i in `locate -r "bin$"`; do find $i \( -perm -4000 -o -perm -2000 \) -type f 2>/dev/null; done # Looks in ‘common’ places: /bin, /sbin, /usr/bin, /usr/sbin, /usr/local/bin, /usr/local/sbin and any other *bin, for SGID or SUID (Quicker search) find / -perm -g=s -o -perm -4000 ! -type l -maxdepth 3 -exec ls -ld {} \; 2>/dev/null # find starting at root (/), SGID or SUID, not Symbolic links, only 3 folders deep, a list with more detail and hide any errors (e.g. permission denied)

Where can written to and executed from? A few ‘common’ places: /tmp, /var/tmp, /dev/shm

find / -writable -type d 2>/dev/null # world-writeable folders find / -perm -222 -type d 2>/dev/null # world-writeable folders find / -perm -o w -type d 2>/dev/null # world-writeable folders find / -perm -o x -type d 2>/dev/null # world-executable folders find / \( -perm -o w -perm -o x \) -type d 2>/dev/null # world-writeable & executable folders

Any “problem” files? Word-writeable, “nobody” files

find / -xdev -type d \( -perm -0002 -a ! -perm -1000 \) -print # world-writeable files find /dir -xdev \( -nouser -o -nogroup \) -print # Noowner files

Preparation & Finding Exploit Code

What development tools/languages are installed/supported?

find / -name perl* find / -name python* find / -name gcc* find / -name cc

How can files be uploaded?

find / -name wget find / -name nc* find / -name netcat* find / -name tftp* find / -name ftp