Feeds

O2 leaks 3G users' mobile numbers to every website visited

Telco launches probe

Boost IT visibility and business value

Updated O2 UK is dishing out its customers' mobile numbers like free sweeties to every website they visit over a 3G connection.

The info leak was highlighted yesterday by O2 customer Lewis Peckover, who set up a little web tool that displays all the HTTP header information sent to sites by connecting web browsers. These strings of data include details such as the URL of the page requested, and the web browser and operating system versions used by the person visiting the site.

For customers browsing on an O2 3G connection, these headers also include their telephone number in an x-up-calling-line-id line - added in by proxy server software most likely running on the telco's network, rather than disclosed by a gadget's browser or software. Enterprising website owners can try to keep a copy of the HTTP header information sent over by visiting browsers and tie it to IP addresses and logins, if applicable.

Rival 3G networks are not appending visitors' phone numbers to the HTTP headers. O2 phones using Wi-Fi won't have the issue, nor will O2 users using web browsers such as Opera, which have their own proxy servers.

From reports on Twitter, BlackBerrys on O2 don't experience the problem because RIM runs its own proxy servers, and neither do O2 customers in Germany and other countries because the telco operates separate proxy servers in each nation.

The mobile number leak also affects GiffGaff and Tesco Mobile customers, whose networks piggyback O2's infrastructure. ®

Updated to add

While O2 says it is still investigating the matter, the number-leaking HTTP header has disappeared from the telco's 3G proxy system. ®

The Essential Guide to IT Transformation

More from The Register

next story
Scotland's BIG question: Will independence cost me my broadband?
They can take our lives, but they'll never take our SPECTRUM
Bring back error correction, say Danish 'net boffins
We don't need no steenkin' TCP/IP retransmission and the congestion it causes
Auntie remains MYSTIFIED by that weekend BBC iPlayer and website outage
Still doing 'forensics' on the caching layer – Beeb digi wonk
NBN Co adds apartments to FTTP rollout
Commercial trial locations to go live in September
Samsung Z Tizen OS mobe is post-phoned – this time for good?
Russian launch for Sammy's non-droid knocked back
Telstra to KILL 2G network by end of 2016
GSM now stands for Grave-Seeking-Mobile network
Seeking LTE expert to insert small cells into BT customers' places
Is this the first step to a FON-a-like 4G network?
What FTC lawsuit? T-Mobile US touts 10GB, $100 family-of-4 plan
Folks 'could use that money for more important things' says CEO Legere
prev story

Whitepapers

Implementing global e-invoicing with guaranteed legal certainty
Explaining the role local tax compliance plays in successful supply chain management and e-business and how leading global brands are addressing this.
The Essential Guide to IT Transformation
ServiceNow discusses three IT transformations that can help CIO's automate IT services to transform IT and the enterprise.
Consolidation: The Foundation for IT Business Transformation
In this whitepaper learn how effective consolidation of IT and business resources can enable multiple, meaningful business benefits.
How modern custom applications can spur business growth
Learn how to create, deploy and manage custom applications without consuming or expanding the need for scarce, expensive IT resources.
Build a business case: developing custom apps
Learn how to maximize the value of custom applications by accelerating and simplifying their development.