NOW READ THIS
("Security Advisory")
Submitted by: Bill Hickey
NCVA List Master
NRT-0333 Vonage Vulnerable to Various Attacks:
Security vendor Sipera Systems has warned that users of the popular Vonage Voice-
Over-IP (VoIP) service could be vulnerable to a wide variety of attacks and issued
four threat advisories.
One of the most serious warnings deals with the Motorola phone adapter used to link
telephones to the Vonage service. The adapter has no way to authenticate incoming
Session Initiation Protocol (SIP) call requests, which means that miscreants can
execute an attack with a simple phone call, Sipera says. "Consequently, an attacker
or spammer can send a SIP message directly to a Vonage customer, from [an] IP address
spoofed to be the server's IP address." Disguised as the SIP server, an attacker can
execute a variety of exploits, including information theft, Sipera says.
In a separate warning, Sipera also said this vulnerability might be used to launch a
denial of service attack on a Vonage user. Vonage users should authenticate incoming
SIP requests before accepting them, the researchers say.
In another "high severity" alert, Sipera warns that attackers can eavesdrop on Vonage
calls without much difficulty. Vonage traffic is often sent over the internet using
unencrypted RTP packets, which can be captured and reconstructed by a third party, the
researchers note. "The availability of several free tools to reconstruct media from
captured RTP packets further increses the threat," Sipera cautions.
Sipera also issued a "medium severity" warning that a weak authentication vulnerability
in Vonage's SIP server may allow an attacker to send spoofed REGISTER messages to the
server. This may make it possible for legitimate users' registration sessions to be
sniffed, copied, and replayed, the security vendor says.
"These vulnerabilities create serious privacy and service availability issues for users,"
says Krishna Kurapati, Sipera founder/CTO and head of Sipera VIPER Lab. "Vonage and
[other VoIP service] customers can no longer assume that their VoIP providers are
automatically securing their services, but they should demand best security practices
be followed as a condition of becoming a customer.
(www.darkreading.com 26OCT07)