BT has sealed a critical security hole in the Home Hub that offered hackers full control of the router, which is in about two million UK homes.
The firm's latest update has kneecapped part of the router's firmware called Remote Assistance, which gives customer support staff admin rights to investigate problems.
A BT spokesman said service will be unaffected by disabling the feature, since support can still access the Home Hub using the separate Remote Access feature. "Remote Assistance" will still appear in the router's menu page, but the link will return an error.
Earlier this month we reported how researchers had exploited a firmware bug to hurdle the Hub's admin password authentication. All it required was for a naive surfer to hit a malicious link.
BT's inhouse security team quickly launched an investigation. The firm had been criticised by the same researchers for failing to respond to a vulnerability in another of its routers reported last year.