Ofcom, the telco regulator, has announced plans to close a technical loophole that poses a threat to mobile users’ privacy and security. The loophole involves the leasing of phone numbers known as Global Titles, which are used by mobile networks for sending and receiving signalling messages to ensure calls and texts reach the intended recipient.
While these signalling messages are typically unseen by mobile users and play a crucial role in supporting billions of calls and text messages worldwide, criminals can exploit Global Titles to intercept and divert communications. This puts mobile users at risk of having their personal data accessed by malicious actors, potentially compromising their security and privacy.
Recognizing the risks associated with Global Titles, the National Cyber Security Centre (NCSC) has urged international cooperation in addressing this issue. As a result, Ofcom has taken the step to ban the leasing of Global Titles with immediate effect, in light of industry-led efforts falling short in mitigating these risks.
Ofcom has identified services such as Home Location Register (HLR) lookup as high-risk areas associated with Global Titles, as they provide access to operational data held by mobile networks. To prevent misuse, Ofcom has issued guidance for number range holders and mobile operators to safeguard against potential data breaches and ensure compliance with relevant data protection legislation.
Natalie Black, Ofcom’s group director for networks and communications, emphasized the importance of safeguarding mobile networks from malicious activities facilitated by leased Global Titles. The ban on new leasing arrangements is immediate, with existing leases set to be phased out by April 22, 2026, to allow legitimate businesses time to transition to alternative arrangements.
Overall, Ofcom’s proactive measures aim to protect mobile users and critical telecoms infrastructure from the risks posed by unauthorized use of Global Titles, reinforcing the importance of cybersecurity in the telecommunications industry.
