Mobile network Three UK's customer details exposed in homepage blunder
Mobile operator Three UK's website was showing visitors other customers' names, postal addresses, phone numbers, email addresses and more – all without asking for a login.
Alarmed Reg reader Chris immediately tweeted at Three to ask what on Earth was going on, querying why Three's site was displaying different people's data to him every time he changed page.
The site was showing him as logged in even though he'd only gone to the mobile operator's homepage.
"When you load their site over your mobile internet connection, it recognises you and automatically logs you in," Chris told us. "I was doing this on my home Wi-Fi (which isn't Three), so it should've required me to log in manually when I first went to their site. I guessed it might've either redirected me to a session for a valid user who was accessing at the same time, or some blip which didn't recognise me and just assigned another user's ID instead."
"I wasn't able to to view any payment details – card or direct debit, and I wasn't able to load any detailed bills to view itemised activity," added Chris. Three claims to have around 10 million registered subscribers.
While our reader waited for a response from Three (it replied to him on Twitter an hour and a half after his initial tweet), he tipped off El Reg. As we investigated, we noticed the company website went down for a little while with the standard "under maintenance" page displayed – and came back up again after about an hour. Chris said other people's data was no longer visible once the site returned.
The nature of the data breach suggests that potentially the entire customer database along with some of the personal data held on file may have been exposed.
Despite repeated contact with Three's PR representatives, none of The Register's questions about the potential size or scale of the breach have been answered.
Judging by the URLs visible in some of the other screenshots Chris sent us, which included the letters /new, the company's techies may have accidentally deployed an under-construction revamp of the site to the mobe firm's production servers. This is merely speculation and Three has not responded to questions on this.
The Information Commissioner's Office was unable to say, at the time of publication, if Three had reported the breach.
An ICO spokesperson told us: “Three has made us aware of an incident and we will be making enquiries.”
A Three UK spokesperson told us: “A small number of customer[s] have reported an issue to us regarding my3. We have blocked access to my3 while we investigate the issue.”
Three UK wanted to make it known that only four people had complained about being able to view any random Three customer's personal data by simply visiting its website and not even needing to log in. El Reg is very happy to make this clear.
source theregister
Latest Jobs
-
- Account Director | Cyber Security Consulting | UK - South East
- London
- N/A
-
Account Director | Cyber Security Consulting - Financial Services | UK - South East. New Role due to Growth We are looking for an experienced Account Director to develop and expand existing relationships across the financial services sector, working with investment firms, asset managers, private equity groups and strategic partners to deliver intelligent cyber consulting and a bespoke Cyber product offerings. You will act as a trusted advisor, helping organisations strengthen digital resilience, manage third-party and regulatory risk and adopt a proactive approach to cyber assurance. Key Responsibilities Manage a defined portfolio of financial clients, understanding business priorities and aligning tailored cyber solutions. Drive new client engagement while nurturing existing partnerships through a consultative, long-term approach. Present the benefits of advanced cyber services including threat intelligence, vulnerability management, incident readiness, and continuous risk monitoring. Collaborate with technical and delivery teams to ensure smooth engagement from proposal through to implementation and ongoing support. Prepare proposals, negotiate commercial terms, and clearly articulate value and business outcomes. Build trusted relationships at senior and board level. Ideal Profile Strong background in cybersecurity, consulting, or risk management within financial services. Skilled communicator with proven success managing and growing key accounts. Able to translate complex technical insight into commercial and strategic value for clients. Confident engaging with senior stakeholders and decision makers. Please note: Sponsorship is not available.
-
- SOC Analyst- Level 2- Hybrid Greater London
- London
- N/A
-
SOC Analyst- Level 2- Hybrid Greater London New opportunity created through continued growth. We’re looking for a SOC Analyst (Level 2) to strengthen a growing managed security team. You’ll work hands-on with Microsoft Sentinel and Defender XDR, investigating alerts, responding to incidents, and helping improve how clients stay protected. This role is ideal for someone who enjoys unravelling security events, thinking critically under pressure, and making a real difference day to day. What you’ll do · Investigate and respond to security activity across SIEM and endpoint tools · Analyse network and log data to uncover real threats · Support automation initiatives to streamline response processes · Help maintain visibility, data flow, and performance across SOC platforms What you’ll need · Practical experience using Microsoft Sentinel and Defender XDR · Confident working with KQL or similar query languages · Understanding of attacker tactics and response techniques · SC-200 certifications would be nice. · Experience supporting multiple customer environments Please note: Sponsorship is not available.
-
- Senior SOC Engineer - UK - New role due to growth
- London
- N/A
-
Senior SOC Engineer – New role due to growth We are hiring a Senior SOC Engineer to take the lead across security operations for a growing managed service. You will lead detection, response and onboarding activity across multiple clients, helping shape how the SOC evolves. Expect variety; from fine-tuning alerts and threat hunting to supporting customers and mentoring junior analysts. What you’ll bring · Strong experience across SIEM, EDR, and threat detection tools · Confident working with customers in a managed service environment · Skilled in scripting or query languages such as KQL or PowerShell · Knowledge of frameworks like NIST, ISO27001, MITRE ATT&CK · Calm communicator with a problem-solving mindset · Experience with Azure Lighthouse or delegated access models · Prior involvement in automation or SOC improvement projects Location: South East England- Hybrid role Please note: Sponsorship cannot be offered now or in the future.
-
- SENIOR Cyber Risk Consultant. Cyber Risk consultancy - the right way. UK. Hybrid - Remote first
- United Kingdom
- N/A
-
Senior Cyber Risk Consultant needed. New position due to growth Seeking a passionate Cyber Security Risk Consultant who enjoys helping clients make a different to their business. Dedicated training budgets, Unlimited holiday structured career path, Work life balance guaranteed Cyber Risk consultancy done the right way. A successful individual will have experience working with clients to identify business cyber security risk. This is a remote first opportunity which means you will spend the majority of your time working remotely. You will however spend some time meeting clients as well as meeting up with the team on a monthly basis.. Some of the nice to have certifications. CRISC, ISO27001 Lead implementer, CISA, CISM, CISSP Unable to offer Visa sponsorship now or in the future.