Vulnerabilities at AT&T, T-Mobile and Sprint Could Have Exposed Customer Data

Vulnerabilities at AT&T, T-Mobile and Sprint Could Have Exposed Customer Data

Last week was not a good week for telecommunications companies.

Security researchers have uncovered security flaws with systems at AT&T, Sprint and T-Mobile that could have left customer data accessible to bad actors.

The flaws impacting AT&T and T-Mobile were first reported. In T-Mobile's case, an "engineer mistake" between Apple's online storefront and T-Mobile's account validation API allowed for an unlimited number of attempts on an online form, which would allow a hacker to use commonly-available tools to guess an account PIN or the last four digits in a customer's social security numbers, in what's called a brute-force attack. The vulnerability has since been fixed.

A similar problem occurred with phone insurance company Asurion and its AT&T customers. An online form would allow anyone with a customer's phone number to access a form that allowed them unlimited guesses to guess a customer's passcode, leaving it vulnerable to another brute-force attack. The vulnerability has since been fixed.

At Sprint, security researchers were able to access an internal portal because of a "weak, easy-to-use usernames and passwords," compounded with the lack of two-factor authentication. Once in, the researcher was reportedly able to access customer account information for Sprint, Boost Mobile, and Virgin Mobile. The researcher also reported that anyone who gained access could make changes to customer accounts and that customers PINs could be brute-forced.

A Sprint spokesperson confirmed the vulnerability to TechCrunch, and noted that it didn't believe that any customers were affected by the vulnerability. The spokesperson said they were working to fix the issue.

About the Author

Sydny Shepard is the Executive Editor of Campus Security & Life Safety.

Featured

  • The Evolution of IP Camera Intelligence

    As the 30th anniversary of the IP camera approaches in 2026, it is worth reflecting on how far we have come. The first network camera, launched in 1996, delivered one frame every 17 seconds—not impressive by today’s standards, but groundbreaking at the time. It did something that no analog system could: transmit video over a standard IP network. Read Now

  • From Surveillance to Intelligence

    Years ago, it would have been significantly more expensive to run an analytic like that — requiring a custom-built solution with burdensome infrastructure demands — but modern edge devices have made it accessible to everyone. It also saves time, which is a critical factor if a missing child is involved. Video compression technology has played a critical role as well. Over the years, significant advancements have been made in video coding standards — including H.263, MPEG formats, and H.264—alongside compression optimization technologies developed by IP video manufacturers to improve efficiency without sacrificing quality. The open-source AV1 codec developed by the Alliance for Open Media—a consortium including Google, Netflix, Microsoft, Amazon and others — is already the preferred decoder for cloud-based applications, and is quickly becoming the standard for video compression of all types. Read Now

  • Cost: Reactive vs. Proactive Security

    Security breaches often happen despite the availability of tools to prevent them. To combat this problem, the industry is shifting from reactive correction to proactive protection. This article will examine why so many security leaders have realized they must “lead before the breach” – not after. Read Now

  • Achieving Clear Audio

    In today’s ever-changing world of security and risk management, effective communication via an intercom and door entry communication system is a critical communication tool to keep a facility’s staff, visitors and vendors safe. Read Now

  • Beyond Apps: Access Control for Today’s Residents

    The modern resident lives in an app-saturated world. From banking to grocery delivery, fitness tracking to ridesharing, nearly every service demands another download. But when it comes to accessing the place you live, most people do not want to clutter their phone with yet another app, especially if its only purpose is to open a door. Read Now

New Products

  • Connect ONE’s powerful cloud-hosted management platform provides the means to tailor lockdowns and emergency mass notifications throughout a facility – while simultaneously alerting occupants to hazards or next steps, like evacuation.

    Connect ONE®

    Connect ONE’s powerful cloud-hosted management platform provides the means to tailor lockdowns and emergency mass notifications throughout a facility – while simultaneously alerting occupants to hazards or next steps, like evacuation.

  • FEP GameChanger

    FEP GameChanger

    Paige Datacom Solutions Introduces Important and Innovative Cabling Products GameChanger Cable, a proven and patented solution that significantly exceeds the reach of traditional category cable will now have a FEP/FEP construction.

  • Camden CM-221 Series Switches

    Camden CM-221 Series Switches

    Camden Door Controls is pleased to announce that, in response to soaring customer demand, it has expanded its range of ValueWave™ no-touch switches to include a narrow (slimline) version with manual override. This override button is designed to provide additional assurance that the request to exit switch will open a door, even if the no-touch sensor fails to operate. This new slimline switch also features a heavy gauge stainless steel faceplate, a red/green illuminated light ring, and is IP65 rated, making it ideal for indoor or outdoor use as part of an automatic door or access control system. ValueWave™ no-touch switches are designed for easy installation and trouble-free service in high traffic applications. In addition to this narrow version, the CM-221 & CM-222 Series switches are available in a range of other models with single and double gang heavy-gauge stainless steel faceplates and include illuminated light rings.