Defcon Corporate teleconferences and other sensitive video feeds traveling over internet are a lot more vulnerable to interception thanks to the release of free software tools that offer penetration testers and attackers a point-and-click interface.
At the Defcon hacker conference in Las Vegas, the Viper Lab researchers demonstrated new additions to UCSniff, a package of tools for sniffing internet-based phone conversations. The updates offer tools that streamline the process of intercepting video feeds, even when they are embedded in voice-over-internet-protocol traffic.
Taking a page from movies like The Thomas Crown Affair, the researchers showed how a companion tool called VideoJak can be used to tamper with video surveillance feeds in museums and other high-security settings. As several hundred conference attendees looked on, they displayed a live feed of a water bottle that was supposed to be a stand in for precious diamond egg. When someone tried to touch the bottle, the video caught the action in real time.
Then they fired up VideoJak. When the bottle was touched again, the video, which presumably would be piped to a security guard, continued to show the bottle was safe and sound.
"We used UCSniff to actually capture valid stream for 20 seconds and then we played it against the security guy receiving the traffic," Ostrom, who is director of Sipera's Viper Labs, said in an interview afterward. "So he saw the room was just sitting there unmolested while the person was actually taking the diamond egg."
A separate demo showed a live teleconference that was being secretly intercepted so the video feeds of both participants could be logged in real time. Both attacks convert the intercepted feeds to a raw H.264 video file and from there to a simple AVI file.
UCSniff is a man-in-the-middle attack tool that runs on a laptop that is plugged into the network being probed. From there, a VLAN hopper automatically traverses the virtual local area network until it accesses the part that carries VoIP calls. Once the tool has gained unauthorized access, it automatically injects spoofed ARP, or address resolution protocol, packets into the network, allowing all voice and video traffic to be routed to the laptop.
Obviously, the tool requires physical access to the network being targeted, but in cases of corporate espionage, such scenarios aren't all that uncommon. While video streams can be encrypted Ostrom estimated only one in 20 of his clients typically bother.
Enterprises can also prevent the man-in-the-middle attacks by disabling a network feature known as gratuitous ARP on VoIP phones. The new tools have a way to defeat that measure by blocking ACK messages from reaching the device. That causes the phones to reregister with the server. During the reboot process, the software tampers with the TFTP, or trivial file transfer protocol, to turn gratuitous ARP back on.
"This all happens in less than 30 seconds," Ostrom said during the demo. "If the user is watching the phone, they might be able to catch it, but they might not think anything of it. We basically pwn the phone. We can change anything on the phone we want to." ®