Copyright Security-Assessment.com 2004 Security-Assessment.com Hacking VoIP Is your Conversation confidential? by Nick von Dadelszen and Darren Bilby
Copyright Security-Assessment.com 2004 Security-Assessment.com VoIP Trends VOIP becoming more popular and will increase in future Many ISPs and Teleco’s starting to offer VoIP services Like most other phone calls, it is presumed to be confidential
Copyright Security-Assessment.com 2004 Security-Assessment.com Types of Phones SoftPhone HardPhone
Copyright Security-Assessment.com 2004 Security-Assessment.com Typical VoIP Architecture
Copyright Security-Assessment.com 2004 Security-Assessment.com Attacks Against VoIP Multiple attack avenues: –Standard traffic capture attacks –Bootp attacks –Phone-based vulnerabilities –Management interface attacks
Copyright Security-Assessment.com 2004 Security-Assessment.com Consequences of Attacks Consequences of VoIP attacks include: –Listening or recording phone calls –Injecting content into phone calls –Spoofing caller ID –Crashing phones –Denying phone service –VoIP Spamming
Copyright Security-Assessment.com 2004 Security-Assessment.com VoIP Protocols H.323 –Earlier protocol used, though still used today –Provides for encryption and authentication of data SIP –Digest authentication based on HTTP, but many times not enabled –No encryption MGCP –Relies on IPSEC for security, but most current phones don’t support IPSEC
Copyright Security-Assessment.com 2004 Security-Assessment.com Use of VLANS Cisco recommends separate VLANs for data and voice traffic To ease implementation, many phones allow sharing of network connections with desktop PCs VoIP allows the use of SoftPhones installed on desktop PCs Therefore cannot separate voice traffic from the rest of the network
Copyright Security-Assessment.com 2004 Security-Assessment.com Capturing VoIP Data Ethereal has built-in support for some VoIP protocols Has the ability to capture VoIP traffic Can dump some forms of VoIP traffic directly to WAV files.
Copyright Security-Assessment.com 2004 Security-Assessment.com
Copyright Security-Assessment.com 2004 Security-Assessment.com
Copyright Security-Assessment.com 2004 Security-Assessment.com Audio Capture
Copyright Security-Assessment.com 2004 Security-Assessment.com Other Tools Vomit –Injects wave files into VoIP conversations Tourettes –Written by a staff member of a customer for fun –Injects random swear words into a conversation
Copyright Security-Assessment.com 2004 Security-Assessment.com Example Phone Exploit CAN Cisco ATA-186 Web interface could reveal sensitive information Sending a POST request consisting of one byte to the HTTP interface of the adapter reveals the full configuration of the phone, including administrator password IP Phones – Another thing to patch!
Copyright Security-Assessment.com 2004 Security-Assessment.com Caller ID Spoofing Caller ID is based on a Calling Party Number (CPN) This is always sent when a call is placed A privacy flag tells the receiver whether to show the number or not Have always been able to spoof Caller ID but needed expensive PBX equipment to do so. With VoIP PBX software, spoofing is easier Has repercussions for phone authentication