Apple Online Store Security Flaw Exposed PINs of T-Mobile Customers

A security flaw in Apple's online store exposed the account PINs of more than 72 million T-Mobile customers, reports BuzzFeed News.

The vulnerability was discovered by security researchers Phobia and Nicholas "Convict" Ceraolo, who also found a similar flaw in the website for phone insurance company Asurion that exposed AT&T account PINs.

Both Apple and Asurion fixed the website flaws that left the PINs vulnerable after learning about them from BuzzFeed News. Apple opted not to provide further comment on the situation, but told BuzzFeed News that it is "very grateful to the researchers who found the flaw."

tmobileapplepage

The page on Apple's site that let hackers brute force PINs, via BuzzFeed News

PINs, or passcodes, are numbers that are used as an additional account security measure by many carriers in the United States. Mobile device PINs are typically a last line of defense for a cellular account as both carrier websites and support staff will ask for the PIN for confirmation before making account changes.

SIM hacking, which uses social engineering to get carrier support staff to transfer a person's phone number to a new SIM, has become increasingly prevalent due to the number of accounts (bank, email, social media, etc.) that are tied to a person's phone number. A PIN is used as a defense mechanism against SIM hacking, which means exposed PINs can be particularly dangerous.

Accessing the T-Mobile PINs on Apple's website involved a brute force attack where a hacker used software to input multiple different numeric combinations to guess the proper one.

As BuzzFeed News explains, after initiating a T-Mobile iPhone purchase on the Apple online store and selecting monthly payment options through T-Mobile, Apple's site directs users to an authentication form asking for a T-Mobile number and account PIN or last four digits of a social security number (which most carriers use in place of a PIN when one has not been set).

The page allowed for infinite entry attempts into the PIN field, enabling the brute force attack that let hackers guess PINs associated with a T-Mobile phone number.

The security vulnerability appears to have been limited to T-Mobile accounts, as the same validation page for other carriers on Apple's site uses a rate limit that locks access to the form for 60 minutes after five to 10 incorrect entries. Given that the other carrier pages had rate limiting enabled, it's likely Apple made an error on the T-Mobile page.

According to Ceraolo, the vulnerability is likely due to an engineering mistake made when connecting T-Mobile's account validation API to Apple's website.

A similar vulnerability on Asurion's website exposed an unspecified number of AT&T account PINs. An AT&T spokesperson said that it is working with Asurion to investigate the issue and will "take any additional action that may be appropriate."

A phone number was required for both of these attacks, limiting the number of people who may have been impacted, but AT&T and T-Mobile customers who are concerned about their account safety should choose a new PIN.

Tags: T-Mobile, AT&T

Top Rated Comments

mistasopz Avatar
54 months ago
But forum members told me that Apple had the best security. Well except for those times when they didn't. Like the root password gate where you didn't have to put a password in to gain root access.
Score: 41 Votes (Like | Disagree)
RoobyRoobyRoo Avatar
54 months ago
But forum members told me that Apple had the best security. Well except for those times when they didn't. Like the root password gate where you didn't have to put a password in to gain root access.
Having the best security =/= flawless security. No tech company is completely flawless. But go ahead and chastise Apple for not being absolutely perfect, because that's so productive.
Score: 24 Votes (Like | Disagree)
Doctor Q Avatar
54 months ago
Four digits isn't a very long PIN. Even if the software now locks access to the form for 60 minutes after five to 10 incorrect entries, it doesn't block the exploit, just slow it down.

It seems to me that a bot could try 10 guesses for one phone number, which would lock the form for that phone number, then immediately switch to another phone number. If the phone number is locked for the IP address, it could use another IP address too.

If so, let's try a little math here: Rather than a bot trying one phone number and 10,000 different PINs in rapid succession to break it, it could try five to ten PINs for every phone number it's working on in the first hour, then try another five to ten PINs for every phone number in the second hour, and so on. In as few as 42 days it could crack every phone number. If it was trying to crack 10,000 phone numbers, it would succeed on an average of 238 phone numbers per day. That's still pretty vulnerable.
Score: 17 Votes (Like | Disagree)
mi7chy Avatar
54 months ago
Apple don't care about security because even after several security incidents customers are brain washed into thinking Apple is flawless.
Score: 10 Votes (Like | Disagree)
zakarhino Avatar
54 months ago
Security issue after security issue for T-Mobile and many carriers in general. Remember when T-Mo Germany said they don't need to salt their passwords because their security is "that good"? Or when it was discovered that it's very easy to get access to a T-Mo account AND clone people's sims because T-Mo doesn't have very good security practices beyond asking for the last 4 of your SSN? I've heard stories of people phoning up carriers under the guise of being a store employee and they get access to all sorts of information without thorough identity verification!

I know Apple are the guys that purportedly screwed up here but when you look at T-Mobile's security in general, it doesn't have a very good track record, it should have never been possible for the Tmo verification API to allow unlimited requests without a time limit. These carriers need to seriously update their security practices. Just accepting the last 4 digits of your social security number is no longer a viable option.
Score: 8 Votes (Like | Disagree)
nvmls Avatar
54 months ago
Squeeze that privacy/security coin Timo!
Score: 6 Votes (Like | Disagree)

Popular Stories

iphone 14 pro max vs 13 max 2

Camera Comparison: iPhone 14 Pro Max vs. iPhone 13 Pro Max

Thursday September 29, 2022 7:44 am PDT by
The iPhone 14 Pro and Pro Max introduce some major improvements in camera technology, adding a 48-megapixel lens and low-light improvements across all lenses with the new Photonic Engine. We've spent the last week working on an in-depth comparison that pits the new iPhone 14 Pro Max against the prior-generation iPhone 13 Pro Max to see just how much better the iPhone 14 Pro Max can be. Subscrib ...
tony blevins car

Apple Procurement VP Departs Company After Vulgar TikTok Comment

Thursday September 29, 2022 12:38 pm PDT by
Tony Blevins, Apple's vice president of procurement, is set to depart the company after he made a crude comment about his profession in a recent TikTok video, reports Bloomberg. Blevins was in a video by TikTok creator Daniel Mac, who was doing a series on the jobs of people he spotted with expensive cars. After seeing Blevins in an expensive Mercedes-Benz SLR McLaren, Mac asked Blevins what ...
Dark Sky App Featured

Dark Sky Removed From iOS App Store Ahead of Upcoming Shutdown

Wednesday September 28, 2022 4:27 pm PDT by
The Dark Sky weather app that's owned by Apple is no longer available for download in the U.S. App Store, suggesting that it has been removed ahead of schedule. Apple acquired Dark Sky back in March 2020 and has since incorporated elements of the app into the Weather app available on the iPhone (and soon, the iPad). Dark Sky remained available for purchase as a standalone weather app...
adaptive transparency airpods pro

iOS 16.1 Beta Brings Adaptive Transparency to Original AirPods Pro

Thursday September 29, 2022 1:08 pm PDT by
The third beta of iOS 16.1 that was released earlier this week expands the Adaptive Transparency feature introduced with the second-generation AirPods Pro to the original AirPods Pro. As noted on Reddit, first-generation AirPods Pro owners who also have the AirPods beta software will now see an "Adaptive Transparency" toggle in the AirPods section of the Settings app. The 5A304A beta...
tim cook malala

Tim Cook: Not Too Long From Now, You'll Wonder How You Led Your Life Without AR

Thursday September 29, 2022 7:26 am PDT by
Speaking at Università Degli Studi di Napoli Federico II in Naples, Italy, Apple CEO Tim Cook said that not too long from today, people will wonder how they led a life without augmented reality, stressing the "profound" impact it will have on the not so distant future. At the university, Cook was awarded an Honorary Degree in Innovation and International Management and also sat down for a...
iOS 16 Wallpaper Spectrum Feature

Five Wallpaper Apps to Check Out for iOS 16's New Lock Screen Depth Effect

Thursday September 29, 2022 9:08 am PDT by
One of the biggest new features in iOS 16 is a completely redesigned iPhone Lock Screen. The new Lock Screen is entirely customizable, letting you change the colors and fonts, add widgets and new wallpapers, and more to make your iPhone uniquely yours. Of course, even before iOS 16, you could customize your Lock Screen with a wallpaper of your choice. iOS 16 takes the Lock Screen wallpaper...
maxresdefault

Apple Responds to Video Testing Crash Detection Feature With Junkyard Vehicles

Friday September 30, 2022 9:11 am PDT by
The Wall Street Journal's Joanna Stern recently traveled to Michigan to test Apple's new crash detection feature on the iPhone 14 and Apple Watch Ultra. In response, Apple provided some additional information about how the feature works. Stern recruited Michael Barabe to crash his demolition derby car with a heavy-duty steel frame into two unoccupied vehicles parked in a junkyard — a 2003...
iphone 14 iphone 14 plus in hand feature

iPhone 14 Is Secretly Hiding a Beloved Mac Feature

Friday September 30, 2022 3:24 am PDT by
The iPhone 14 and iPhone 14 Pro models bring over a longstanding Mac feature, but the setting to enable it is off by default. The feature, which is actually a new accessibility option, allows the iPhone to play a startup chime like the Mac. When enabled, the sound comes alongside a new shutdown chime. The Mac has featured a startup chime since 1987's Macintosh II, and the iconic "bong"...
Hero0005

Best Apple Deals of the Week: M2 MacBook Air Hits New All-Time Low Price at $1,049, Plus Sales on AirPods Pro and More

Friday September 30, 2022 9:05 am PDT by
This week's best Apple deals focus on the AirPods Pro, AirPods Pro 2, and M2 MacBook Air, including numerous all-time low prices on these devices. You'll also find up to 50 percent off discounts on Anker and Eufy accessories on Amazon. Note: MacRumors is an affiliate partner with some of these vendors. When you click a link and make a purchase, we may receive a small payment, which helps us...
iPhone 15 to Switch From Lightning to USB C in 2023 feature sans arrow

Kuo: iPhone 14 Pro Max Popularity Could Lead to More Differentiation Between iPhone 15 Pro and iPhone 15 Pro Max

Wednesday September 28, 2022 10:22 am PDT by
Apple has seen high demand for the 6.7-inch iPhone 14 Pro Max, which could lead the company to further differentiate the next-generation iPhone 15 Pro and Pro Max, according to Apple analyst Ming-Chi Kuo. Apple could add exclusive features to the iPhone 15 Pro Max in an effort to encourage more people to purchase the larger and more expensive device. Kuo last week said that Apple asked...