[solved] Is linux secure? Find out with a shell server!

alex6z · Tux's lil' helper Joined: 20 Jul 2005 Posts: 119

ssh -p 1222 public@98.214.151.249
ssh -p 1222 public0@98.214.151.249
ftp is on port 30021.

To fix jammed accounts:
ssh -p 1222 ag@98.214.151.249

Most TCP ports are firewalled except FTP and HTTP. UDP, and TCP above port 32768 are open for outgoing data. UDP/TCP ports 30000-30099 are accessable from the outside.

See the /CRACK_ME file.

If you get root and follow the directions in /CRACK_ME, then I'll send you $5 or a .36oz 90% silver half dollar in the mail.

There was once this guy who had a box where there was a php exploit or something and the apache account was compromised. He wanted to reformat because of this. I thought this was silly because it's just the apache user, not the whole system.

So, was my opinion good? That's what this shell server is for

IF you break in to the root account easily then reformating might have been the right thing to do then, do you think?

enjoy

It's a 133MHz box that I got from the trash.

I added a NEW TOY!:
in "/home/public/EXPLOITABLE_FUNSTUFF/" there is an exploitable version of the exiftags-1.00 tool set which is setgid "cracked". If you want to have a little fun, you can try to gain access to the "cracked" user group. The GLSA concerning exiftags-1.00 is here: http://security.gentoo.org/glsa/glsa-200712-17.xml

Happy hacking.

frostschutz · Advocate Joined: 22 Feb 2005 Posts: 2977 Location: Germany

NeddySeagoon · Posted: Tue Dec 25, 2007 2:38 pm Post subject:

alex6z,

looks like your box is down already
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

Simba7

alex6z · Tux's lil' helper Joined: 20 Jul 2005 Posts: 119

GNUtoo · Veteran Joined: 05 May 2005 Posts: 1919

you could make a little space on this box...

alex6z · Tux's lil' helper Joined: 20 Jul 2005 Posts: 119

People like to fill the disk. Just look in /home/public or /tmp for large files and delete them. I think somebody filled .bash_history to 2GB for some reason. Just delete it.

bunder · Bodhisattva Joined: 10 Apr 2004 Posts: 5947

is that a forkbomb script i see? :lol:

_________________

alex6z · Tux's lil' helper Joined: 20 Jul 2005 Posts: 119

Yes I put fork.c there to save everyone the trouble of making their own and having it not really do much It also exits on its own after 5 minutes..

bunder · Bodhisattva Joined: 10 Apr 2004 Posts: 5947

alex6z · Tux's lil' helper Joined: 20 Jul 2005 Posts: 119

You can copy fork.c and change it. It's limited with limits.conf so the fork bomb doesn't do much and fork.c exits after 5 minutes so that it doesn't stay running forever and you don't lock yourself out as easily.

alex6z · Tux's lil' helper Joined: 20 Jul 2005 Posts: 119

Has everyone lost interest already?

Only a couple logins today

Naib · Posted: Sat Dec 29, 2007 11:39 pm Post subject:

don't worry it will heat up again

just re-grouping
_________________
#define HelloWorld int
#define Int main()
#define Return printf
#define Print return
#include <stdio>
HelloWorld Int {
Return("Hello, world!\n");
Print 0;

nendzd · n00b Joined: 10 Apr 2006 Posts: 68

I logged in and poked around. No ideal how to "hack" root or anything.. Someone deleted your fork thing by the way.

Dagger · Retired Dev Joined: 11 Jun 2003 Posts: 765 Location: UK

hehe i will gladly take a look on it over the weekend

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95% of all computer errors occur between chair and keyboard (TM)
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alex6z · Tux's lil' helper Joined: 20 Jul 2005 Posts: 119

If I had a faster computer, maybe I could make a public distcc server out of it? I have a 1.3GHz Duron that isn't being used, is it worth it? How about a Pentium III 1.00GHz?

frostschutz · Advocate Joined: 22 Feb 2005 Posts: 2977 Location: Germany

Are you aware of the bandwidth requirements of distcc? In a local network it's fine, but public over the internet doesn't much sense... regarding both cpu cycles that a single machine can provide to "the public" and internet traffic...

fog · n00b Joined: 28 Sep 2003 Posts: 49

This is good fun! I'd just worry about people using it to attack remote hosts or such, but I guess the firewall would do it.

I'm no hacker, but I want to give this a try anyway...

alex6z · Tux's lil' helper Joined: 20 Jul 2005 Posts: 119

NeddySeagoon · Posted: Fri Jan 18, 2008 2:29 pm Post subject:

alex6z,

The helper nodes get sent the preprocessor output to compile and return the binary to the control node for linking.
Lets take a kernel as a worked example.

The kernel is about 250Mb uncompressed but including its .o files, so to compile a kernel for me I'm going to send you some 200+Mb and download the balance. My uplink is 440kbits/sec, (55kB/sec) so it takes me 4545 seconds to upload the source for you to build (using 200Mb at 55kB/sec). Thats 1.25 hours.
However, I can build a kernel in less than 15 min without your help. So, to break even, I need an upload speed of 275kB/sec.
Then we have the build time on your box and the download of the binaries.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

alex6z · Tux's lil' helper Joined: 20 Jul 2005 Posts: 119

That 250MB is for when you enable ALL the kernel options, isn't it?

If you enable every kernel option, how long does it take to compile?

fog · n00b Joined: 28 Sep 2003 Posts: 49

NeddySeagoon · Posted: Fri Jan 18, 2008 5:43 pm Post subject:

alex6z,

Very true - thats the entire kernel source tree.

However the preprocessor makes the sources bigger so its swings and roundabouts. I was trying to illustrate the amount of data to be moved and the time it would take.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

alex6z · Tux's lil' helper Joined: 20 Jul 2005 Posts: 119

Now the question is: Does distcc server cache the data that is sent to it to compile, specifically the header files.

I don't really know how distcc works, but I'm guessing that the file that needs to be compiled, and all the header files that go along with it, are send to the distcc server. Then the server sends back the object file. If the distcc server caches the header files then not that much data would need to be sent twice. Or could it be that the preprocessor runs on the client and the preprocessed data is send to the distcc server to get compiled?

So if you have a slow computer, and you're trying to compile a package that's say 30MB, and distcc caches the data that is send to it, it could be worth while, no? If you have a 50KB/sec upload, it should only take 10 minutes to upload the whole thing (30MB) to the distcc server, right?

AS far as I know using distcc doesn't ever slow down compiling, does it? The object files don't have to be compiled in order, do they?

frostschutz · Advocate Joined: 22 Feb 2005 Posts: 2977 Location: Germany

distcc slows down compiling horribly when there is a slow distcc server. distcc sends a job to this server and expects an answer back ASAP because otherwise the compiling process simply cannot continue. This means you need both a fast network and a fast computer to do the compile. Compile results do depend on each other, you cannot simply tell a server oh you compile this half and I compile this half and we'll put it together later.