More Related Content Similar to Hacking and Attacking VoIP Systems - What You Need To Know (20) Hacking and Attacking VoIP Systems - What You Need To Know1. Hacking and Attacking VoIP Systems
What You Need To Worry About
Dan York, CISSP
VOIPSA Best Practices Chair
September 27, 2007 2. Privacy Availability
Compliance Confidence
Mobility Cost Avoidance
Business Continuity
© 2007 VOIPSA and Owners as Marked p. 6. TDM security is relatively simple...
PSTN
Gateways
TDM
Switch
Physical
Wiring
Voicemail
© 2007 VOIPSA and Owners as Marked p. 7. VoIP security is more complex
Desktop
Operating PSTN
E-mail
PCs
Systems Gateways
Systems
Network Web
Firewalls
Switches Servers
Standards
PDAs
Voice over Wireless
IP Devices
Instant
Messaging
Directories
Internet
Databases
Physical
Voicemail
Wiring
© 2007 VOIPSA and Owners as Marked p. 8. What is the Industry Doing to Help?
Security Vendors VoIP Vendors
“The Sky Is Falling!” “Don’t Worry, Trust Us!”
(Buy our products!) (Buy our products!)
© 2007 VOIPSA and Owners as Marked p. 9. Voice Over IP Security Alliance (VOIPSA)
• www.voipsa.org – 100 members from VoIP and security industries
• VOIPSEC mailing list – www.voipsa.org/VOIPSEC/
• “Voice of VOIPSA” Blog – www.voipsa.org/blog
• Blue Box: The VoIP Security Podcast – www.blueboxpodcast.com
• VoIP Security Threat Taxonomy
• Best Practices Project underway now
Security
Research
Market and Social Classification Best Practices Outreach
Objectives and Taxonomy of for VoIP Communication
Constraints Security Threats Security of Findings
Security
System
Testing
Published Active Now Ongoing
LEGEND
© 2007 VOIPSA and Owners as Marked p. 11. Security concerns in telephony are not new…
Image courtesy of the Computer History Museum
© 2007 VOIPSA and Owners as Marked p. 12. Nor are our attempts to protect against threats…
Image courtesy of Mike Sandman – http://www.sandman.com/
© 2007 VOIPSA and Owners as Marked p. 13. Security Aspects of IP Telephony
Media /
Voice
Manage TCP/IP Call
ment Network Control
PSTN
Policy
© 2007 VOIPSA and Owners as Marked p. 14. Media
Eavesdropping
Degraded Voice Quality
Encryption
Virtual LANs (VLANs)
Packet Filtering
© 2007 VOIPSA and Owners as Marked p. 15. Signaling
Denial of Service
Impersonation
Toll Fraud
Encryption
Encrypted Phone Software
Proper Programming
© 2007 VOIPSA and Owners as Marked p. 16. Management
Web Interfaces
APIs!
Phones!
Encryption
Change Default Passwords!
Patches? We don’t need...
© 2007 VOIPSA and Owners as Marked p. 18. LAN
Internet
© 2007 VOIPSA and Owners as Marked p. 19. What about SPIT? (“SPam over Internet Telephony”)
• Makes for great headlines, but not yet a significant threat
• Fear is script/tool that:
–Iterates through calling SIP addresses:
• 111@sip.company.com, 112@sip.company.com, …
• Opens an audio stream if call is answered (by person or voicemail)
–Steals VoIP credentials and uses account to make calls
SPAM
• Reality is that today such direct connections
are generally not allowed
• This will change as companies make greater use
of SIP trunking and/or directly connect IP-PBX
systems to the Internet (and allow incoming calls
from any other IP endpoint)
• Until that time, Telemarketers have to initiate unsolicited calls through the PSTN to reach
their primary market: slows them down and adds cost
© 2007 VOIPSA and Owners as Marked p. 20. The Challenge of SIP Trunking
PSTN
SIP Service
Provider
Internet
IP-PBX
LAN
© 2007 VOIPSA and Owners as Marked p. 24. Tools, tools, tools...
• UDP Flooder • Asteroid
• IAX Flooder • enumIAX
• IAX Enumerator • iWar
• ohrwurm RTP Fuzzer • StegRTP
• RTP Flooder • VoiPong
• INVITE Flooder • Web Interface for SIP Trace
• AuthTool • SIPScan
• BYE Teardown • SIPCrack
• Redirect Poison • SiVuS
• Registration Hijacker • SIPVicious Tool Suite
• Registration Eraser • SIPBomber
• RTP InsertSound • SIPsak
• RTP MixSound • SIP bot
• SPITTER
© 2007 VOIPSA and Owners as Marked p. 27. Security Suggestions for Asterisk
1. TLS-encrypted SIP
• needs SIP over TCP first...
2. Secure RTP (SRTP)
• there’s a patch
3. SRTP Key Exchange
• sdescriptions now, DTLS or potentially ZRTP in the future
If Asterisk is configured to use
4. Figure out the phone configuration mess IMAP as its backend storage for
• so that the web servers on the phones can be disabled voicemail, then an e-mail sent to a
• auto configuration is a start, but how secure are the config files? user with an invalid/corrupted MIME
body will cause Asterisk to crash
5. Identity when the user listens to their
• RFC 4474 (SIP Identity) voicemail using the phone.
6. Watch out for the APIs and the apps
• always fun when a rolodex app can crash your phone system!
7. Toll fraud??
8. Testing with tools?
© 2007 VOIPSA and Owners as Marked p. 29. Security Links
• VoIP Security Alliance - http://www.voipsa.org/
–Threat Taxonomy - http://www.voipsa.org/Activities/taxonomy.php
–VOIPSEC email list - http://www.voipsa.org/VOIPSEC/
–Weblog - http://www.voipsa.org/blog/
–Security Tools list - http://www.voipsa.org/Resources/tools.php
–Blue Box: The VoIP Security Podcast - http://www.blueboxpodcast.com
• NIST SP800-58, “Security Considerations for VoIP Systems”
– http://csrc.nist.gov/publications/nistpubs/800-58/SP800-58-final.pdf
• Network Security Tools
– http://sectools.org/
• Hacking Exposed VoIP site and tools
– http://www.hackingvoip.com/
© 2007 VOIPSA and Owners as Marked p. 31. Speaker Introduction – Dan York
Dan York, CISSP, is the Best Practices Chair for the VOIP Security Alliance where he leads the project to develop
and document a concise set of industry-wide best practices for security VoIP systems. He is also heading up
VOIPSA's move into quot;social mediaquot; with the launch of the Voice of VOIPSA group weblog. Additionally, York is
the producer of Blue Box: The VoIP Security Podcast where each week he and co-host Jonathan Zar discuss
VoIP security news and interview people involved in the field.
Most recently he served as Director of IP Technology reporting to the CTO of Mitel Corporation and focused on
emerging VoIP technology and VoIP security. As chair of Mitel's Product Security Team, he coordinates the
efforts of a cross-functional group to communicate both externally and internally on VoIP security issues,
respond to customer inquiries related to security, investigate security vulnerability reports, and monitor security
standards and trends. Previously, York served in Mitel Product Management bringing multiple products to
market including Mitel's secure VoIP Teleworker Solution in 2003.
His writing can also be found online at his weblog,
Disruptive Telephony.
© 2007 VOIPSA and Owners as Marked p. 32. Other Best Practices
Media / Voice
TCP/IP
Manage Call
Network
• Network
ment Control
Policy
PSTN
–Networks should be evaluated for readiness to carry VoIP traffic.
–Secure mechanisms should be used for traversal of firewalls.
• Phone Sets
–Set software loads should be encrypted and tamper-proof.
–Sets should run the minimum of services required.
–Connection of a set to the system must require an initial authentication and authorization.
• Servers
–Servers should be incorporated into appropriate patch management and anti-virus systems.
–Sufficient backup power should be available to maintain operation of telephony devices (and necessary
network infrastructure) in the event of a power failure.
• Wireless
–All wireless devices should implement WPA and/or WPA2 versus WEP.
© 2007 VOIPSA and Owners as Marked p.