O2 Privacy Flaw Sends Users' Mobile Numbers to Visited Websites

As noted by think broadband, a privacy flaw in the way UK carrier O2 handles web traffic on mobile devices has resulted in users' mobile numbers being sent to any website visited from the device as part of the headers in the HTTP requests. While O2 is apparently still investigating the situation, it appears to have the potential for significant privacy-related issues.

If you're reading this news article using your O2 mobile phone, you'll be pleased to know that O2 have already sent us your mobile phone number within the HTTP headers which normally contain information about how content can be displayed on your device. These headers are not normally seen by users, and usually not logged by most websites, but the flaw allows malicious sites to get more personal information about you than you may be willing to share.

For example, if you open an e-mail which includes references to external images, the mere action of opening the e-mail would divulge your phone number. This could be used by anyone undertaking a phishing attack or other scam to get more information from you. The opportunity to abuse this is potentially endless.

The issue was discovered by Twitter user @lewispeckover, who then set up a website to allow users to see what headers are being sent as part of their HTTP requests to websites.

He now notes that the headers coming from his device appear to have stopped showing his mobile phone number, although O2 has yet to issue an official statement on the matter. The company's Twitter account is continuing to blast out responses to concerned users, noting only that the company is looking into the situation and will issue an update when it knows more.

The issue is not exclusive to the iPhone and has the potential to affect all mobile data on the second-largest carrier in the UK, although some users have reported that they are not seeing their mobile numbers appearing in their HTTP request headers. The issue has the potential to for a significant impact on UK iPhone users, as O2 has proven to be a popular choice for iPhone users dating back to its status as the exclusive iPhone carrier in the UK when the device originally launched back in 2007.

Those familiar with the UK's privacy laws have indicated that mobile phone numbers are not considered protected information, but the disclosure of such numbers as part of standard HTTP requests does have the potential to carry implications for users.

Top Rated Comments

(View all)
Avatar
114 months ago
I've really not been impressed by O2 in recent years. I first joined them in 2006, but ever since then, their network coverage in the 20 mile radius of here (near Bath) hasn't improved one bit. The 3G coverage is absolutely awful. If you aren't in a major town or a city, you have no chance of 3G with O2, only dial-up speed GPRS. Not even EDGE in most cases.

Everything Everywhere are very good, but Three (in the south of England at least) are best by far for 3G coverage.

Perhaps if O2 spent more money on, well, being a service provider and improving their network, rather than all that "priority moments" crap, they might increase their 3G coverage.
Score: 6 Votes (Like | Disagree)
Avatar
114 months ago

Not so in my o2 account with an iPhone using iOS 5.0.1 via Safari.


It wasn't inserted into the user agent, it was a separate header: "x-up-calling-line-id".
Score: 4 Votes (Like | Disagree)
Avatar
114 months ago
The "O" is for "Oops!"
Score: 4 Votes (Like | Disagree)
Avatar
114 months ago
I'm appalled they let this in.

I'm thrilled they fixed it so quickly.

I'm going to treat o2 with a bit more suspicion from here on out.
Score: 2 Votes (Like | Disagree)
Avatar
114 months ago

I am now intrigued though as to who the "trusted partners" are. O2 themselves and BT Openzone are the only ones I can think of.


One is Bango, the company that runs O2's adult verification software and thought sending credit card numbers in plaintext over http was a good idea.

O2 might "trust" them. I don't.

Phazer
Score: 2 Votes (Like | Disagree)
Avatar
114 months ago
I'm perfectly happy with O2, I've found the coverage decent and I don't get loads of junk text messages from them like I did from Vodafone*. This latest gaffe is a bit annoying, but whatever, as a business owner my details are well and truly 'out there' for all the lowlife to exploit anyway. Bring it on scumbags.

*The junk texts don't stop when you leave Vodafone. The other day I received a text that said "Come back to Vodafone and we'll give you a free Windows 7 laptop". If there's one thing that would be guaranteed to STOP me going back to them, it's the threat of a crappy low end piece of junk with a crappy low end OS turning up at my house.
Score: 2 Votes (Like | Disagree)

Top Stories

iPhone 12 Pro in Graphite and iPhone 12 in Blue Shown Off in Unboxing Videos

Monday October 19, 2020 8:20 am PDT by
While the iPhone 12 Pro does not launch until Friday, we now have an early unboxing video of the device courtesy of Twitter account DuanRui, providing a closer look at the shiny new flat-edge design and sleek Graphite color option. Ben Geskin re-uploaded the unboxing video to YouTube, which we've embedded below: Geskin has also uploaded an unboxing video of the iPhone 12 in Blue: ...

Kuo: iPhone 12 Pro Demand Higher Than Expected

Sunday October 18, 2020 10:39 pm PDT by
TF International Securities analyst Ming-Chi Kuo released a research note this morning detailing what he's seen with the volume of iPhone 12 and iPhone 12 Pro pre-orders in the first weekend of sales. Kuo had previously indicated that Apple's estimated shipment allocations for the new iPhone models placed the iPhone 12 at the top with 40-45% of inventory allocation (up from 15-20%). However, ...

Apple's New MagSafe Charger and Cases Begin Arriving to Customers

Saturday October 17, 2020 10:10 am PDT by
Apple's new MagSafe charger and cases have begun arriving to some customers earlier than expected, and images of the accessories have started to surface on Twitter. The photos provide a first look at the products in real-world use. As of writing, some MagSafe cases are also available for pickup at select Apple Stores in countries like the United States, Canada, and Germany. Filip...

HomePod Mini Cable is Non-Detachable, Ends With USB-C Connector for Use With Included 20W Power Adapter

Friday October 16, 2020 12:45 pm PDT by
While not detailed in the tech specs, MacRumors can confirm that Apple's new HomePod mini features a non-detachable power cable that ends with a USB-C connector for use with the 20W power adapter included in the box. With the switch to USB-C, the HomePod mini could potentially be powered by a wider range of devices and peripherals, ranging from MacBooks to USB-C battery packs with enough...

Samsung Mocks Apple for Ditching Power Adapters With iPhone 12 Lineup

Thursday October 15, 2020 11:51 am PDT by
Samsung on its social channels is mocking Apple for removing the power adapter from the iPhone 12 lineup and other iPhone models, pointing out the fact that the Samsung Galaxy smartphones continue to ship with a power adapter. "Included with your Galaxy," reads a Samsung Facebook post that features a picture of a power adapter. Apple notably is no longer providing power adapters or...

New Google App Feature Lets You Hum a Song to Search for It

Saturday October 17, 2020 4:05 am PDT by
Google has added a new feature to its Search app that allows you to hum a song that's stuck in your head, and then use the company's machine learning algorithm to try and identify it. In the Google app or using the Google Search widget, tap the mic icon and say "what's this song?" or click the "Search a song" button. Then start humming the tune for 10-15 seconds. When you're done, the...

Brazilian Certifications Suggest iPhone 12 Mini Features 2,227mAh Battery and iPhone 12 Has 2,815mAh Battery

Friday October 16, 2020 1:08 pm PDT by
Apple's iPhone mini has the shortest battery life out of all the iPhones in the iPhone 12 lineup due to its small size, but Apple has not provided public information about the battery's capacity. A regulatory filing from Brazil, however, suggests the iPhone 12 mini has a battery capacity of 2,227mAh. The same regulatory information says the iPhone 12 features a 2,815mAh battery, which is...

iPhone 12 Pro Pre-Orders Already Selling Out With Delivery Times Pushing Into November

Friday October 16, 2020 6:35 am PDT by
Apple today opened pre-orders for the 6.1-inch models of the iPhone 12 and iPhone 12 Pro through its website and the Apple Store app, and estimated delivery times are already slipping into November for select configurations in the United States. Customers ordering a SIM-free/Pacific Blue/128GB version of the iPhone 12 Pro, for example, are already facing an estimated delivery window of...

Hands-On With Apple's MagSafe Charger for iPhone 12

Monday October 19, 2020 11:54 am PDT by
Alongside the new iPhone 12 models, Apple introduced a MagSafe charger that attaches to the back of the iPhones using magnets embedded both in the charger and in the iPhone. It allows for speedier charging and paves the way for a portless iPhone in the future. MagSafe chargers are shipping out and are in some Apple retail locations now, and we picked one up to check it out. Subscribe to the ...

Apple Offering Free AirPods With iPhone 11 Purchase in India as Part of Diwali Celebration

Friday October 16, 2020 12:35 pm PDT by
Apple today launched a new Diwali promotion in India that will see the company providing customers with a set of AirPods with the purchase of any iPhone 11 model. The new iPhone 12 models are not part of the promotion. Apple is offering the standard AirPods With Charging Case free with purchase, but customers can choose to upgrade to the AirPods with Wireless Charging Case or the AirPods Pro....