security without firewall? Seems possible

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eMadman
I'm unsure as to whether or not the topic i'm coverign here is against the AUP. If it is, please say so and either a moderator or I will remove the thread immediately.

One of my courses this semester is Network+... and the prof likes to dabble into network security on occasion. That sparked a bit of interest in me so I decided to see what I could do to break into my desktop pc (which btw, doesn't have a firewall). The reason I uninstalled the firewall on the computer is because it was just giving me nothing but major buttaches - plus the ones I tried ended up blocking too much out and outright refused to allow me to run some things even after disabling the software.

Anyways, with that in mind, I decided to let my desktop run the apps I usually have going when it's sitting idly - so azureus and eMule going side by side with a RemotelyAnywhere server and MySQL running as well (I'm too lazy to disable mysql even though i rarely use it). In addition to this, windows update hasn't been run since I installed SP2.

With the system set up, I went onto my laptop and portscanned the sucker. It should be noted that the only way I have of accessing the desktop at this point is via remote control since my mom has already gone to bed.

This is what it found after 15 minutes of scanning (it would probably have found more but i'm using a 11mbps wireless connection right now and the speed isn't ideal):

portscan.jpg


Ports 22, 25, 80, and 139 are the primary ones to worry about since 25, 80 and 139 are the ones most commonly attacked. Port 22 is potentially worrysome because it's used by a remote system administration program called RemotelyAnywhere.

Attempting to access port 80 seems to be useless as I can't gain access to it. The exploits for the IIS 5.1 framework that I found have a few errors in the code and won't compile properly. I'm too tired at the moment to see if I can teach myself C and fix the problems - maybe after my exams are over. If I get a chance, I'll try using the exploit libraries on my linux disks.

The ones that caught my eye however, are 1025 and 3306. A quick google search showed that 1025 is related to the RPC exploit (I've already got that patched up and a quick penetration test made certain of it). Another google search for port 3306 revealed that this is potentially related to mysql.

I attempted the standard tests to see if I could gain access to port 3306 and to see whether or not anything was running on it. I managed to gain telnet access but it seems as though nothing was running on that port. In order to do a more thorough test, I'd need to reboot my laptop into Linux to get access to the entire pre-compiled securityfocus and packetstorm exploit libraries and try them one by one. I'm not in the mood to do that at the moment.

Of these ports that are open, only 139 is completely open to access. I figured this by entering the following into command prompt:
Code:
C:\> net use J: \\192.168.2.26\SharedDocs

there was actually a lot more to this than just this one line but for simplicity's sake, I'll leave it at this
That created a network drive under My Computer in which I had complete access to the SharedDocs folder. Keep in mind that my laptop is not on the workgroup at home. I *think* it gave me access because my username and password on both the laptop and desktop are the same... but I'm not certain about that.

Now... i got access to the folder... but then again, it *is* being shared... Anyways, just to further test this, I ran a utility called enum. The information it gave was scary

enum.jpg

enum2.jpg


The end conclusion. I've got one massive vulnerability caused by enabling windows file sharing and thus NetBios. The others are less common and would be difficult for most script kiddies to break. It seems that as long as you keep the crap running in the background to a minimum, the only really major thing most people will have to worry about is being DOS'ed. To counter that, all you got to do is configure your system not to respond to ping.

For protection from the outside world, I have only my router which has most ports opened already (the netbios ones excepted).


I had fun doing this for the past hour and a half and I'll probably try this again but with more testing and a more thorough procedure to test my desktop. I'll also see if I can do anything to compromise ZoneAlarm on that computer.

ps. sorry for the image sizes - I only have ms paint on my laptop for image handling
 
idunno - these results were of my computer without any protections running at all and the system was more or less unpatched since sp2.

Best protection imo is intelligent computer usage. Don't install unnecessary crap, don't go to stupid websites and for the love of god, don't open strange files. It seems to have worked for me for the past few months. Even more so since i told my sister that I won't fix it any more if she screws it up. Since then, she stopped downloading stupid crap, she doesn't go to websites her dumbarse friends send her and she no longer opens strange files. Over the past few months I have had no problems with the pc, no more psycho DOS attacks crashing the firewall programs I used to use and my system is relatively stable.
 
So, was the firewall from SP2 turned on? If it is, than I am in trouble, as I only have that firewall turned on, and I have a firewall on my router turned on.
 
cardude2004
So, was the firewall from SP2 turned on? If it is, than I am in trouble, as I only have that firewall turned on, and I have a firewall on my router turned on.
The only protection program running on that computer is Norton Antivirus 8.0 Corporate edition. The sp2 firewall is always shutdown on my computers because its annoying as crap and it doesn't work very well. I attacked my desktop from within the lan so the router's firewall wasn't going to do anything to protect it.

Frankly, I'm starting to find that firewalls in a home environment are completely unnecessary as long as you don't download a lot of crap. They get over the top annoying once you have a bunch of web apps installed and running... plus they randomly tend to slow down my computers a lot for no apparent reason. The only firewall I ever have running is my router - and I usually have that set up not to protect my my desktop through the dmz settings.
 
3306 is the port used to access the MySQL databases. Did you try telnet-ing to it and running SQL queries?

When you say that you have ports open on your router, have you initiated Port Address Translation?
 
GilesGuthrie
3306 is the port used to access the MySQL databases. Did you try telnet-ing to it and running SQL queries?
I didn't consider running the sql queries via telnet - i'll give that a shot tonight. I learned sql 2 years ago and haven't touched it since. Have any suggestions for queries i can try?

When you say that you have ports open on your router, have you initiated Port Address Translation?
I'm not sure that I follow. I just realized that i had the ports disabled in favour of setting that computer up as a DMZ.
 
emad
I didn't consider running the sql queries via telnet - i'll give that a shot tonight. I learned sql 2 years ago and haven't touched it since. Have any suggestions for queries i can try?

Well, this document suggests that you type:

mysql -h host -u user -p

It should then say "Enter password:". You type the password in and it will give you a welcome message.

emad
I'm not sure that I follow. I just realized that i had the ports disabled in favour of setting that computer up as a DMZ.

Well, Port Address Translation is how you configure the router to direct inbound connections to a specific device on the LAN. So, if you have a web server running on 192.168.1.104, you will open PAT on the router, and define the destination address for inbound connections on Port 80 as being the local (private) address of your web server.

Your router will drop any inbound packets where it doesn't know how to route them, so switching off PAT will secure your network from unsolicited inbound traffic.

The most important word in that sentence was "unsolicited"...
 
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