Ofcom cracks down on mobile network loophole used to intercept text messages

Ofcom has said it is taking “world-leading” action to prevent criminals maliciously using mobile networks to intercept text messages, including bank security codes.

The regulator has announced a ban on the leasing of special types of phone numbers known as Global Titles, which are used by mobile networks to support services by ensuring messages and calls reach the intended recipient.

The telecoms regulator said that, until now, Global Titles could be leased out to third parties, leading to a technical loophole whereby criminals could potentially get hold of and intercept messages, including security codes sent to bank customers via SMS.

In response, Ofcom said it is now banning the leasing of Global Titles.

‘Significant’

Natalie Black, the regulator’s group director for network and communications, said: “We are taking world-leading action to tackle the threat posed by criminals gaining access to mobile networks.

“Leased Global Titles are one of the most significant and persistent sources of malicious signalling.

“Our ban will help prevent them falling into the wrong hands – protecting mobile users and our critical telecoms infrastructure in the process.”

Ofcom said the risk posed by the leasing of Global Titles has been recognised by organisations including the UK’s National Cyber Security Centre (NCSC), but that so far, industry-led efforts to address the issue have not been effective.

It said this is why it is stepping in to introduce the leasing ban.

Security risks

NCSC chief technical officer Ollie Whitehouse said: “Today’s announcement marks an important step in the support of our mission to make the UK the safest place to live and work online.

“This technique, which is actively used by unregulated commercial companies, poses privacy and security risks to everyday users, and we urge our international partners to follow suit in addressing it.

“As the UK’s national technical authority for cyber security, we also congratulate Ofcom on their continued global leadership in this critical area.”