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A Guide to Internet Security: Becoming an Uebercrackerand Becoming an UeberAdmin to stop Uebercrackers.Author: Christopher Klaus <cklaus@shadow.net>Date: December 5th, 1993.Version: 1.1This is a paper will be broken into two parts, one showing 15 easy stepsto becoming a uebercracker and the next part showing how to become aueberadmin and how to stop a uebercracker. A uebercracker is a term phrasedby Dan Farmer to refer to some elite (cr/h)acker that is practicallyimpossible to keep out of the networks.Here's the steps to becoming a uebercracker.Step 1. Relax and remain calm. Remember YOU are a Uebercracker.Step 2. If you know a little Unix, you are way ahead of the crowd and skippast step 3.Step 3. You may want to buy Unix manual or book to let you know whatls,cd,cat does.Step 4. Read Usenet for the following groups: alt.irc, alt.security,comp.security.unix. Subscribe to Phrack@well.sf.ca.us to get a backgroundin uebercracker culture.Step 5. Ask on alt.irc how to get and compile the latest IRC client andconnect to IRC.Step 6. Once on IRC, join the #hack channel. (Whew, you are half-waythere!)Step 7. Now, sit on #hack and send messages to everyone in the channelsaying "Hi, Whats up?". Be obnoxious to anyone else that joins and asksquestions like "Why cant I join #warez?"Step 8. (Important Step) Send private messages to everyone asking for newbugs or holes. Here's a good pointer, look around your system for binaryprograms suid root (look in Unix manual from step 3 if confused). Afterfinding a suid root binary, (ie. su, chfn, syslog), tell people you have anew bug in that program and you wrote a script for it. If they ask how itworks, tell them they are "layme". Remember, YOU are a UeberCracker. Askthem to trade for their get-root scripts.Step 9. Make them send you some scripts before you send some garbage file(ie. a big core file). Tell them it is encrypted or it was messed up andyou need to upload your script again.Step 10. Spend a week grabbing all the scripts you can. (Dont forget to beobnoxious on #hack otherwise people will look down on you and not give youanything.)Step 11. Hopefully you will now have atleast one or two scripts that getyou root on most Unixes. Grab root on your local machines, read youradmin's mail, or even other user's mail, even rm log files and whatevertemps you. (look in Unix manual from step 3 if confused).Step 12. A good test for true uebercrackerness is to be able to fake mail.Ask other uebercrackers how to fake mail (because they have had to pass thesame test). Email your admin how "layme" he is and how you got root and howyou erased his files, and have it appear coming from satan@evil.com.Step 13. Now, to pass into supreme eliteness of uebercrackerness, you bragabout your exploits on #hack to everyone. (Make up stuff, Remember, YOU area uebercracker.)Step 14. Wait a few months and have all your notes, etc ready in your roomfor when the FBI, Secret Service, and other law enforcement agenciesconfinscate your equipment. Call eff.org to complain how you were innocentand how you accidently gotten someone else's account and only lookedbecause you were curious. (Whatever else that may help, throw at them.)Step 15. Now for the true final supreme eliteness of all uebercrackers, yougo back to #hack and brag about how you were busted. YOU are finally atrue Uebercracker.Now the next part of the paper is top secret. Please only pass to trustedadministrators and friends and even some trusted mailing lists, Usenetgroups, etc. (Make sure no one who is NOT in the inner circle of securitygets this.)This is broken down on How to Become an UeberAdmin (otherwise know as asecurity expert) and How to stop Uebercrackers.Step 1. Read Unix manual ( a good idea for admins ).Step 2. Very Important. chmod 700 rdist; chmod 644 /etc/utmp. Installsendmail 8.6.4. You have probably stopped 60 percent of all Uebercrackersnow. Rdist scripts is among the favorites for getting root byuebercrackers.Step 3. Okay, maybe you want to actually secure your machine from theelite Uebercrackers who can break into any site on Internet.Step 4. Set up your firewall to block rpc/nfs/ip-forwarding/src routingpackets. (This only applies to advanced admins who have control of therouter, but this will stop 90% of all uebercrackers from attempting yoursite.)Step 5. Apply all CERT and vendor patches to all of your machines. You havejust now killed 95% of all uebercrackers.Step 6. Run a good password cracker to find open accounts and close them.Run tripwire after making sure your binaries are untouched. Run tcp_wrapperto find if a uebercracker is knocking on your machines. Run ISS to makesure that all your machines are reasonably secure as far as remoteconfiguration (ie. your NFS exports and anon FTP site.)Step 7. If you have done all of the following, you will have stopped 99%of all uebercrackers. Congrads! (Remember, You are the admin.)Step 8. Now there is one percent of uebercrackers that have gainedknowledge from reading some security expert's mail (probably gained accessto his mail via NFS exports or the guest account. You know how it is, likethe mechanic that always has a broken car, or the plumber that has thebroken sink, the security expert usually has an open machine.)Step 9. Here is the hard part is to try to convince these security expertsthat they are not so above the average citizen and that by now giving outtheir unknown (except for the uebercrackers) security bugs, it would be aservice to Internet. They do not have to post it on Usenet, but shareamong many other trusted people and hopefully fixes will come about andnew pressure will be applied to vendors to come out with patches.Step 10. If you have gained the confidence of enough security experts,you will know be a looked upto as an elite security administrator that isable to stop most uebercrackers. The final true test for being a ueberadminis to compile a IRC client, go onto #hack and log all the bragging andhelp catch the uebercrackers. If a uebercracker does get into your system,and he has used a new method you have never seen, you can probably tellyour other security admins and get half of the replies like - "That bugbeen known for years, there just isn't any patches for it yet. Here's myfix." and the other half of the replies will be like - "Wow. That is veryimpressive. You have just moved up a big notch in my security circle."VERY IMPORTANT HERE: If you see anyone in Usenet's security newsgroupsmention anything about that security hole, Flame him for discussing itsince it could bring down Internet and all Uebercrackers will now have itand the million other reasons to keep everything secret about security.Well, this paper has shown the finer details of security on Internet. It hasshown both sides of the coin. Three points I would like to make that wouldprobably clean up most of the security problems on Internet are as thefollowing:1. Vendors need to make security a little higher than zero in priority.If most vendors shipped their Unixes already secure with most known bugsthat have been floating around since the Internet Worm (6 years ago) fixedand patched, then most uebercrackers would be stuck as new machines getadded to Internet. (I believe Uebercracker is german for "lame copy-catthat can get root with 3 year old bugs.") An interesting note is thatif you probably check the mail alias for "security@vendor.com", you willfind it points to /dev/null. Maybe with enough mail, it will overfill/dev/null. (Look in manual if confused.)2. Security experts giving up the attitude that they are above the normalInternet user and try to give out information that could lead to pressureby other admins to vendors to come out with fixes and patches. Mostsecurity experts probably don't realize how far their information hasalready spread.3. And probably one of the more important points is just following thesteps I have outlined for Stopping a Uebercracker.Resources for Security:Many security advisories are available from anonymous ftp cert.org.Ask archie to find tcp_wrapper, security programs. For more informationabout ISS (Internet Security Scanner), email cklaus@shadow.net.Acknowledgements:Thanks to the crew on IRC, Dan Farmer, Wietse Venema, Alec Muffet, ScottMiles, Scott Yelich, and Henri De Valois.Copyright:This paper is Copyright 1993, 1994. Please distribute to only trustedpeople. If you modify, alter, disassemble, reassemble, re-engineer or haveany suggestions or comments, please send them to:cklaus@shadow.net [ Pobierz całość w formacie PDF ]