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Virgin Media patches routers after researchers find flaw

Virgin Media has patched its wireless routers to fix a flaw that could allow attackers to gain unauthorised administrative-level access to the devices

Researchers from Context Information Security were able to gain administrative-level access the Super Hub 2 and Super Hub 2AC routers made by Netgear after reverse engineering software for the devices.

Context’s Jan Mitchell and Andy Monaghan discovered vulnerabilities in a feature allowing users to create backups of their custom configurations, such as port forwarding and dynamic domain name system (DNS) settings, which could be restored at a later date.

While configuration backups were encrypted, the researchers found that the private encryption key was the same across all hubs in the UK. This meant that an attacker with access to the administrative interface of a user’s hub could download a configuration file, add instructions to enable remote access and restore the file to the hub.

Once this process was completed, an attacker could access the device remotely and monitor all internet traffic to and from devices connected to that home network such as PCs, phones and tablets.

Monaghan, a principal security researcher at Context, said the Super Hub represents the default home router offering from one of the UK’s largest internet service providers (ISPs) and is therefore present in millions of UK households, making it a prime target for attackers.

“While ISP-provided routers like this are generally subject to more security testing than a typical off-the-shelf home router, our research shows that a determined attacker can find flaws such as this using inexpensive equipment,” he said.

On discovering the flaw, Context immediately notified Virgin Media. After working with Context and Netgear to verify and fix the vulnerability, Virgin Media rolled out a patch at the end of May 2017 as part of a scheduled firmware update.

This means all older Super Hub routers have been patched automatically, while newer models were issued with the updated version of the software.

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“ISPs will always be at the mercy of their hardware suppliers to some extent,” said Mitchell, a senior researcher at Context.  

“Recent press coverage of attacks such as the Mirai worm highlights the importance to suppliers of carrying out independent security testing of their products to reduce the likelihood of exploitation in production devices. Thankfully, Virgin Media was quick to respond to Context’s findings and start the remediation process,” he said.

“We would like thank Virgin Media for their professionalism and responsiveness in working with Context to fix this issue,” the researchers wrote in a blog post detailing their findings.

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