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  • unauthorised access to a network

    We have a std Windows domain a firewall to keep the bad guys out, we also have a wireless network NOT on the company network, but on its own adsl line for clients to use in a meeting etc, i would like to know if a client plugged his laptop into our network, what damage could he actually do, i know he'd get an IP number and the ability to browse, but he couldn't access the servers as he's not on our domain, but given the fact that he could be neo (matrix joke) is it possible he could at the worst delete files, and if so how?

    Regards

  • #2
    Re: unauthorised access to a network

    If he/she has hacking experiences, sure it's possible.
    Or if he/she has an virus on the machine you can have a big problem
    Marcel
    Technical Consultant
    Netherlands
    http://www.phetios.com
    http://blog.nessus.nl

    MCITP(EA, SA), MCSA/E 2003:Security, CCNA, SNAF, DCUCI, CCSA/E/E+ (R60), VCP4/5, NCDA, NCIE - SAN, NCIE - BR, EMCPE
    "No matter how secure, there is always the human factor."

    "Enjoy life today, tomorrow may never come."
    "If you're going through hell, keep going. ~Winston Churchill"

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    • #3
      Re: unauthorised access to a network

      I'm aware if they have a virus, we have a problem. I know all our servers are uptodate with AV but i know thats not the point, as for the hackers, how could they hack it , i'm not into hacking so am not au fait with the tequniques

      Thanks

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      • #4
        Re: unauthorised access to a network

        If i'm picking this up right you have a seperate ADSL connection that has no connection to your network whatsoever for business customers to use.

        Is this connected to the internal interface on your firewall??

        Is it connected in anyway to your network other than being in the same building??

        If no then you have the same risk as anyone else on the net has of being attacked. Make sure your firewall rules are spot on and no one can gain access.

        If yes then we are in a tottally different ball game. Giving vistors access to your network should be a no no. Disconnect them immediately.

        You could employ the services of an ethical hacker to try and hack your system from the ADSL line but this does involve alot of trust on them.

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        • #5
          Re: unauthorised access to a network

          I'm not going to tell you how to hack...
          However, you can hire a security consultant for an penetration test.
          He can tell you all you're current problems and how to fix it.
          Marcel
          Technical Consultant
          Netherlands
          http://www.phetios.com
          http://blog.nessus.nl

          MCITP(EA, SA), MCSA/E 2003:Security, CCNA, SNAF, DCUCI, CCSA/E/E+ (R60), VCP4/5, NCDA, NCIE - SAN, NCIE - BR, EMCPE
          "No matter how secure, there is always the human factor."

          "Enjoy life today, tomorrow may never come."
          "If you're going through hell, keep going. ~Winston Churchill"

          Comment


          • #6
            Re: unauthorised access to a network

            i agree with dumber and i wont give explicit details, but i will give some scenarios that are not too far from possible and not too difficult... (assuming you know how to use a keyboard)

            lets say you have some SQL servers... they will become very apparent quickly. if you dont know why, im not gonna tell you why. lets say one were to do an etherape capture of the packets going to and fro an SQl server with a query, you can get the SA password and the names of the dB's...

            do i need to explain why that sucks?

            just the simple act of getting a DHCP assigned address is dangerous enough... the DHCP server gives you the address of itself (amongst others) and also your primary DNS. in an AD environment, there is a very good chance that the primary DNS is a DC, as well as the secondary. this is enough for concern.

            if wullieb1's scenario is close to reality, then you really need to set up multiple IP pools for isolation of your AD org from the public internet access. if you internal IP operates on a 192.168.xx.yy scheme, then create a pool for the segmented computers on the 172.120.xx.yy network and forbid the two from crossing unless a firewall permits it...
            its easier to beg forgiveness than ask permission.
            Give karma where karma is due...

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            • #7
              Re: unauthorised access to a network

              There are some nice cheap switches available that support VLANs. So, get one of these and have an ADSL router (not wireless) and a separate wireless access point.

              We setup a network where the student common room had wireless internet access for free, and the office network used the same ADSL router for their web access. This was secured by means of VLAN, which made the port that the wireless access point was on could "see" the port the ADSL router was on, and could not see any other ports on the VLAN switch.

              The office LAN ports on the switch could all see each other, but the VLAN was setup so that it could not see the common room's wireless access point. Additionally, the office ports could all see the ADSL router's port. The router issued DHCP.

              Hope that made sense!

              In this way, I believe there is no way the common room can "see" any of the equipment in the office, nor could viruses or anything.
              Best wishes,
              PaulH.
              MCP:Server 2003; MCITP:Server 2008; MCTS: SBS2008

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