Linux Priv Esc Notes

A collection of notes on Linux Privilege Escalation. Some will lead to r00t, some will help moving laterally, all depends on the end-goal. Trying to avoid the 'How to do it' steps, focusing on 'What to do' instead. Like most of the content on this site, these are put together for personal use but feel free to grab and share because sharing is caring. I'll try to update this as often as I can as this is my go-to

What's available to me immediately

• sudo roles to run programs as another user? root?
• What other users on the system (cat /etc/passwd, cat /etc/shadow, ls /home, ls $HOME/../)
  • Try obvious passwords, blank passwords. Try fuzzing
  • Have password hash? Google it. Try john
  • Look for passwords in command line history (~/{bash,nano,mysql}_history)
  • Look for hard coded passwords in config files (/etc/my.conf)
  • Look for passwords in database dumps (.sql files) or other text extensions (.txt, .csv)
  • Look for hidden private keys
• SUID/GUID executables (find ./ -perm 2000 -o -perm 4000 -type f -print 2>/dev/null)
  • Can I escape to a shell? interactive feature? (nmap -i, vim :!sh, less, more, cp, mv, find)
  • Can I execute another command
    • As command parameter
    • Modifying PATH (e.g. if command calls 'date', 'cp /bin/bash > $HOME/date' and modifying $PATH)
  • Can I use Buffer Overflow to load arbitrary shell code?

What requires some work

Exploits

• Can I download exploit
  • Do I have tools? (wget, curl, links)? Can I access outside world? Internet?
• Can I build one locally?
  • What compilers area available? (C++? C? Python? Java?)
• What can be exploited?
  • Kernel Exploits? Check kernel version. Check release version
  • Outdated / unpatched / vulnerable packages? (rpm -qa |grep <pkg>, dpkg -al |grep <pkg>)
• Any source code available locally?