Unified Communications: Click to talk » DoS

Protecting VoIP Against Three Common Threats

Tony Bradley — Mon, 29 Dec 2008 15:03:02 +0000

There are a number of way, theoretically, that a VoIP communications system could pose a security risk to an enterprise. Let’s face it, while the network administrators have been in the trenches fighting unauthorized access, malware infections, data compromise, and more on a daily basis for the last 10 years, the voice guys have been sitting on a pretty stable and secure platform. While there are huge benefits for an enterprise to migrate from traditional voice to VoIP, those benefits come with a convergence onto that data network that is constantly under attack. That means that the benefits and efficiency of VoIP come with an increase in the number of security threats as well.

That said, attackers are still working on refining how to compromise VoIP for gain. Many of the VoIP weaknesss are proprietary, meaning that they vary from vendor to vendor and make it more difficult for attackers to determine targets. However, there are three VoIP threats that are consistent across pretty much all VoIP implementations and two of the three are actually just new twists on old attacks that were used against traditional voice systems as well.

The three most common VoIP threats are voice spam (sometimes referred to as SPIT (Spam over Internet Telephony), toll fraud (or theft of service), and denial-of-service attacks. For more details about these threats and what you can do to protect your VoIP network against them, check out The Biggest VoIP Securiy Threats – and How to Stop Them.

VoIPshield Finds Flaws With Microsoft UC

Tony Bradley — Fri, 14 Nov 2008 14:29:10 +0000

VoIPshield, a VoIP security solutions company based in Ottawa, Canada, recently discovered vulnerabilities affecting the RTP (Real-time Transport Protocol), a standard data format used for delivery of audio and instant messaging packets over the Internet. Microsoft Office Communications Server 2007, Microsoft Office Communicator, and Microsoft Windows Live Messenger.

This excerpt from the VoIPshield press release explains the issue further: “Most of the attention in enterprise VoIP/UC security has been paid to the control channel, where SIP and other signalling protocols are used,” said Ken Kousky, CEO of security research and analysis firm IP3 and advisor to the VoIP Lab at Illinois Institute of Technology. “Until now, the media stream has been largely ignored by the security community as a source of malicious activity. But attacks from these vectors have the potential to be dangerously persistent and widespread.”

There are an estimated 250 million computers running at least one of these applications. If exploited, the discovered vulnerabilities could result in a DoS (denial-of-service) attack that impacts not just the affected application, but the entire computer system. VoIPshield’s research and disclosure are specific to the Microsoft products mentioned, but they note that these same protocols are used elsewhere and that other VoIP and communications applications are likely impacted by similar vulnerabilities in the media delivery channel.

Cisco Unified Communications Vulnerability

Tony Bradley — Mon, 30 Jun 2008 16:29:37 +0000

Security vulnerability research firm Secunia reports “A vulnerability and a security issue have been reported in Cisco Unified Communications Manager, which can be exploited by malicious people to bypass certain security restrictions or to cause a DoS (Denial of Service).” The vulnerability is only rated as Less Critical by Secunia, so it is not an urgent issue, but users of Cisco Unified Communications Manager should be aware and investigate the availability of patches or updates to address the problem.