Virgin Media SuperHub 3 Vulnerable to Low-Bandwidth DoS

Virgin Media customers with the latest SuperHub 3 router are vulnerable to losing their internet connections through a simple, low-bandwidth denial of service (DoS) attack. The ISP was criticised for using the Intel Puma 6 SoC – notorious for a bug that causes latency spikes and packet losses – in the SuperHub 3 when it was released, and the chipset seems to be causing even more problems, according to ISPReview.

“Feedback on the DSL Reports site and Virgin Media’s Community Forum appears to show that the hardware is also vulnerable to a simple DoS attack, which means that if somebody knows your Virgin IP address then they could hit you with packets of data (i.e. sending random UDP data to the given host with random destination ports) from even a slow broadband connection and this effectively makes your Internet connection unusable,” reports ISPReview’s Mark Jackson.

“In the example above a 1Mbps DoS causes an average latency rise of +20ms (milliseconds) and quite a few high peaks, while 2Mbps delivers +200ms and a huge amount of packet loss (65%), it only gets worse from there,” Jackson writes. “The 2Mbps example is enough to ruin most of your Internet activity until the attack stops (sadly you can’t block this one via the SH3’s firewall).”

At present, there is no way to protect against the DoS vulnerability until Virgin Media issues a security patch.

“According to Ross Allan, who created a piece of software to test the bug, such an attack can’t be stopped by the SH3’s firmwall either because packets from the internet would come through the modem then reach your firewall (i.e. by that point the damage is already done),” Jackson adds.

The vulnerability is also present in other routers that feature the Puma 6 chipset. Virgin Media is yet to comment on the matter, despite its forums full of disgruntled customers.