Implementing Network Security Wireless Security Segway

1
Implementing Network Security Wireless Security
Segway!

• Steve Lamb
• Technical Security Advisor
• http//blogs.msdn.com/steve_lamb
• stephlam_at_microsoft.com

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So whats the problem?

• WEP is a euphemism
• Wired
• Equivalent
• Privacy
• Actually, its a lie
• It isnt equivalent to wired privacy at all!
• How can you secure the air?
• Thus WEPs v.poor
• http//www.isaac.cs.berkeley.edu/isaac/wep-faq.htm
  l

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WLAN Security ChallengesUnsecured WLAN
Company Servers
WLAN Access Point
Mobile Employee
mailtoboss_at_company.tld
mailtoboss_at_company.tld
Evil Hacker
N

• Most wireless LANs are unsecured

4
WLAN Security Challenges Weak Security in 802.11
Static WEP
X7!gk0j3754bf(jv8gF
X7!gk0j 3754bf(jv 8gB)F..
5
Other 802.11 Challenges

• Access Points are dim!
• Key Management (!!!!)
• Manual update never changed!
• Access Control with MAC address filtering
• NO SECURITY!
• Neither is scalable

Authentication
Authorization
Data Protection
Audit
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WLAN Security Challenges Weak Security in 802.11
Static WEP

• Static WEP key easily obtained for encryption /
  authentication

X7!gk0j3754bf(jv8gF
X7!gk0j 3754bf(jv 8gB)F..
X7!gk0j 3754bf(jv 8gB)F..
N
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WLAN Security ChallengesWeak Security in 802.11
Static WEP

• Man in the middle attacks are difficult to detect
  prevent

X7!gk0j37
X7!gk0j37
N
Rogue Network
8
Alternatives to WEP
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VPNs

• Pros
• Familiarity
• Hardware Independent
• Proven Security

• Cons
• Lacks user transparency
• Only user logon (not computer)
• Roaming profiles, logon scripts, GPOs broken,
  shares, management agents, Remote desktop
• No reconnect on resume from standby
• Complex network structure

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VPNs

• More Cons
• No protection for WLAN
• Bottleneck at VPN devices
• Higher management hardware cost
• Prone to disconnection

• Yet more cons! (non-MS VPNs)
• 3rd party licensing costs
• Client compatibility
• Many VPN auth schemes (IPsec Xauth) are as bad as
  WEP!

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PEAP encapsulation
1. Server authenticates to client
2. Establishes protected tunnel (TLS)
3. Client authenticates inside tunnel to
server

• No cryptographic binding between PEAP tunnel and
  tunneled authN method
• Fix constrain client (in GPO) to trust only a
  specific corporate root CA
• Foils potential MitM attacks

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EAP architecture
MS-CHAPv2
TLS
SecurID
TLS
GSS_API Kerberos
PEAP
IKE
MD5
method layer
EAP
EAP layer
PPP
802.3
802.5
802.11
Anything
media layer
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802.1X over 802.11
AuthenticationServer
Supplicant
Authenticator
Access blocked
Gotta get on!
Calculating my key (Wow I just dont understand
this new maths!)
Calculating this guys key
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Session Summary

• Windows XP has great wireless security features
• Theres extensive prescriptive guidance available
  from our website
• Dont be scared of wireless!

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Next Steps

• Find additional security training events
• http//www.microsoft.com/seminar/events/security.
  mspx
• Sign up for security communications
• http//www.microsoft.com/technet/security/signup/
  default.mspx
• Check out Security360
• http//www.microsoft.com/seminar/events/series/mi
  kenash.mspx
• Get additional security tools and content
• http//www.microsoft.com/security/guidance

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Resources

• Microsoft Wi-Fi Page http//www.microsoft.com/wif
  i
• The Unofficial 802.11 Security Web Page
  http//www.drizzle.com/aboba/IEEE/
• Intercepting Mobile Communications The
  Insecurity of 802.11 http//www.drizzle.com/aboba
  /IEEE/wep-draft.zip
• Fluhrer, Mantin, Shamir WEP Paper
  http//www.crypto.com/papers/others/rc4_ksaproc.pd
  f
• WiFi Planet http//www.wi-fiplanet.com/
• Microsoft Solution for Securing Wireless LANs
  with PEAP and Passwords (lt 1 week)
  http//www.microsoft.com/technet/security/guidance
  /peap_0.mspx
• Microsoft Solution for Securing Wireless LANs
  with Certificates
• http//www.microsoft.com/technet/security/prodtech
  /win2003/pkiwire/swlan.mspx
• Wifi for SOHO Environments http//www.microsoft.co
  m/technet/prodtechnol/winxppro/maintain/wifisoho.m
  spx

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Credits

• Thanks to Ian Hellen(MCS) Steve Riley(Corp) as
  I borrowed several of their slides!

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Questions and Answers