Securing Network – Wireless – and Connected Infrastructures

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  • 1. Securing Network Wireless and Connected Infrastructures Fred BaumhardtInfrastructure Solutions Consulting Microsoft Security Solutions, Feb 4 th , 2003

2. Agenda

  • Defining the Datacenter Network Security Problem
  • Penetration Techniques and Tools
  • Network Defence-in-Depth Strategy
    • Perimeter and Network Defences
    • Operating System and Services Defences
    • Application Defences
    • Data Defences

3. The Datacenter Problem We All Face

  • Systems organically grown under Project context
  • No clear best practice from vendors
  • Security often bolted on as an afterthought
  • Fear of change Time to Market

Some Core Systems Internet Systems Departments Extranets Branch Offices Project 1n System 4. The Big Picture of Security

  • OS hardening is only one component of security strategy ANDFirewalls are not a Panacea
  • Entering the Bank Branch doesnt get you into the vault
  • Security relies on multiple things
    • People and skills
    • Process and incident management
    • Internal Technologies E.G. OS, Management Tools, switches, IDS, ISA
    • Edge Technologies Firewalls, ISA, IDS

5. Threat Modelling

  • Internal Users are usually far more dangerous
  • Normal employees have tools, experience, and know your systems after all they use them
  • Customers usually take little internal protection precautions preferring to focus on external Firewalls, and DMZ scenarios for security
  • Data is now being hacked not just systems

6. The First Phase of Hacking

  • Information Gathering and Intelligence
    • Port Scanning Banner Grabbing TCP/IP Packet Profiling TTL Packet Manipulating
    • Researching network structure newsgroup posts, outbound emails, these all hold clues to network design

. 7. The Second Phase of Hacking

  • Analysis of Collected Information
    • Process relevant bits of data about target network
    • Formulate an attack plan
    • For Example: Attacker wont use SUN specific attacks on W2K Boxes, wont use NT Attacks on .NET etc..
    • Hacker Forums, websites, exploit catalogues

8. The Third Phase of Hacking

  • The Compromise
    • OS Specific Attacks
    • Denial of Service Attacks
    • Application Attacks
      • Buffer Overflows
      • URL String Attacks
      • Injection
      • Cross-site Scripting Attacks
  • Compromised system jumps into another

9. Networking and Security

  • The network component is the single most important aspect to security
  • Wireless is based on Radio transmission and reception not bounded by wires
  • Some sort of encryption is thus required to protect open medium
  • Ethernet is also just about as insecure

10. Network Problems ctd

  • Use encryption and authentication to control access to network
    • WEP Wired Equivalent Privacy
    • 802.1X - using Public Key Cryptography
    • Mutually authenticating client and network

11. Securing a Wireless Connection

  • Three major strategies
    • WEP basic low security simple solution
    • VPN use an encrypted tunnel assuming network is untrusted
    • 802.1X family Use PKI to encrypt seamlessly from client to access point
      • Usually complex to implement but then seamless to user
      • Substantial investment in PKI
    • Also vendor specific like Leap

12. What about the wired network ?

  • This is where the hackers kill you
  • Currently a total trust model
    • You can ping HR database, or chairman's PC, or accounting system in Tokyo
  • We assume anyone who can get in to our internal network is trusted and well intentioned
  • Ethernet and TCP/IP is fundamentally insecure

13. VPN

  • Extend the internal network space to clients in internet
  • Extends the security perimeter to the client
  • Main systems are PPTP L2TP/IPSEC

Internet Corporate Net in Reading Router C Router D Corporate Net or Client IP Tunnel Host A Host B 14. How the Architecture Can Prevent Attack Internet Redundant Routers Redundant Firewalls VLAN VLAN VLAN VLAN Redundant Internal Firewalls DNS & SMTP Client and Site VPN Infrastructure Network Internal Active Directory INTERNAL Per imeter INTERNET BORDER VLAN VLAN Messaging Network Exchange VLAN Management Network MOM, deployment VLAN Client Network VLAN VLAN VLAN RADIUS Network Intranet Network - Web Servers Proxy Data Network SQL Server ClustersRemote data center Infrastructure Network Perimeter Active Directory VLAN NIC teams/2 switches NIC teams/2 switches Intrusion Detection . 15. How do I do it ?

    • A Flat DMZ Design to push intelligent inspection outwards
    • ISA layer 7 filtration RPC SMTP HTTP -
    • Switches that act like firewalls
    • IPSec where required between servers
    • Group Policy to Manage Security
    • 802.1X or VPN into ISA servers treating Wireless as Hostile
    • Internal IDS installed

Exchange Server TCP 443: HTTPS Stateful Packet Filtering Firewall Application Filtering Firewall (ISA Server) TCP 80: HTTP Internet TCP 443: HTTPS Or Wireless 16. Call To Action

  • Take Action your network transport is insecure
  • Read and use security operations guides for each technology you use
  • Mail me with questions [email_address]
    • If I didnt want to talk to you I would put a fake address
  • Use the free MS tools to establish a baseline and stay on it
  • Attack yourself you will learn

17. ____________________________________________________________ Wherever you go go securely !