Exclusive What appears to be a glaringly obvious security hole has been blamed for the snatching of 300 domains hosted by one web-hosting firm last year, The Reg has discovered.

A source told El Reg that anyone with a hosting package from 123-Reg, and hence an account control panel, simply had to change the final section of the URL manually (to, for example, /someoneelseswebsite.co.uk) to be able to gain access to another site's emails, name servers and billing.

With access to the admin panel, would-be domain thieves just had to change the contact details for UK registry Nominet to a new email address and then do a failed password request to have a new password sent to the new email address, locking the original owner out, our source claimed.

The .uk registry told The Reg it had "worked with registrars to help them tighten security and prevent a repeat of this incident". Both 123-Reg and Nominet informed us that there was "a query from a registrant" last year that led to Nominet "discovering some irregularities in registration and renewal patterns".

"As part of Nominet's standard operating procedures they locked the affected domains from any transfer or adjustment whilst they investigated further, and with our full support," 123-Reg said in an emailed statement.

Nominet said that its investigations into the issue revealed that "a total of 300 domains had been transferred over to a new registrant in the post-expiry period without the permission of the original registrant".

"We [have] terminated our registrar agreement with one registrar," the dot-UK registry said.

Neither firm would comment on how the the breach had come about or whether the matter had been referred to Britain's Information Commissioner.

Nominet said it couldn't elaborate any further because "we understand there is an ongoing police investigation into this issue". ®

Updated to add

Nominet has been in touch after publication to say that 123-Reg was not the only domain company involved: "Four registrars had domain names that were affected," a spokesman told us.