Verizon text tapping bug run to ground

A bug in Verizon's text messaging system created a means for crackers to snoop on SMS messages, or worse, a security research firm warned last week.

Verizon, while not admitting that anything was amiss, reportedly closed the security loophole last Friday (July 25).

The bug created a means to "easily view mass lists of SMS messages sent to Verizon Cellular customers, including the telephone number and the text in the messages", according to security researchers at ThreeZee Technology.

By signing a phone up for an online login at www.VText.com, crackers exploiting the bug could intercept messages sent to the phone and make charges to a customer's account.

Verizon states that you need to enter both the Tracking ID and the recipient phone number of a message to check on its delivery status on the VText.com site. But by simply entering a message ID, and omitting the phone number, you can track a single message, or hundreds by manipulating the Tracking ID confirmation code, according to ThreeZee Technology.

The previously obscure New Jersey-based ThreeZee said it was withholding full details of the bug "due to security concerns".

In an advisory, Mike Kristovich, security researcher at ThreeZee, describes the security problem as only "moderate". We'd hate to come across a vulnerability he described as critical. At very least the bug would have been a godsend for unscrupulous marketers intent on harvesting mobile phone numbers.

ThreeZee Technology says it first notified Verizon of the problem more than a month ago but has yet to receive a response from the giant US mobile operator.

Verizon has more than 33 million subscribers, making it the largest US mobile network operator.

Wired reports that, following press enquiries, Verizon updated its messaging service on Friday so that confirmation code to SMS couldn't be exploited to get phone numbers or access text messages.

However the fix has removed the ability for legitimate users to confirmed that a text message was sent to the correct phone number, Wired says.

At the time of writing VText.com was temporarily unavailable; hopefully this is a sign that Verizon is in the process of introducing a more satisfactory, permanent fix. ®

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