Virgin Media has assured customers with a Super Hub router that a security flaw has been resolved.
Researchers from Context Information Security found vulnerabilities in the Super Hub 2 and Super Hub 2AC that meant hackers could monitor traffic going in and out of the device.
This was possible because, although configuration back-ups had been encrypted, the private encryption key was identical across all UK hubs.
Virgin Media has now deployed a firmware patch that addresses this shortcoming and assured customers they are no longer at risk.
Speaking to the Register, a spokesperson said: "We take the security of our customers very seriously and experts within our organisation often work with trusted third parties to help keep our customers as secure as possible.
"We thank Context for their professionalism and cooperation."
Andy Monaghan, one of the experts who identified the security flaw, pointed out that the Super Hub is the default home router offering from one of the UK's biggest broadband providers.
This, he said, means it is present in millions of households and therefore 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," Mr Monaghan stated.