Comcast location cell pins to “0000,” serving to attackers make a choice cell phone numbers


Comcast screwup —

Xfinity Mobile deploys fix after frail PIN design fueled number-porting attacks.

Jon Brodkin

A smartphone connected to the Xfinity Mobile service.

A smartphone linked to the Xfinity Mobile carrier.


A defective security option by Comcast on the firm’s cell cell phone carrier made it more straightforward for attackers to port victims’ cell cell phone numbers to totally different carriers.

Comcast in 2017 launched Xfinity Mobile, a cell carrier that makes use of the Verizon Wi-fi community and Comcast Wi-Fi hotspots. Comcast has signed up 1.2 million cell subscribers nonetheless took a shortcut within the design that lets customers switch from Comcast to other carriers.

To port a cell phone line from Comcast to one more wi-fi carrier, a buyer needs to grab his or her Comcast cell memoir number. Carriers usually use PINs to check that a buyer seeking to port a bunch in fact owns the number. But Comcast reportedly location the PIN to 0000 for all its prospects, and there used to be it sounds as if no contrivance for prospects to interchange it. Which contrivance that an attacker who acquired a sufferer’s Comcast memoir number would possibly maybe well perchance also without considerations port the sufferer’s cell phone number to one more carrier.

Comcast informed Ars that “much less than 30” prospects were plagued by the topic, that it has applied a fix, and that the firm will at last roll out a valid PIN-primarily based design to further protect prospects. But Comcast declined to picture the hot fix whatsoever, saying that recordsdata would possibly maybe well perchance also benefit attackers. Comcast additionally did no longer scream when its new PIN-primarily based design would possibly be ready.

Buyer had number hijacked

The topic used to be detailed the day gone by in aWashington Put upcolumn that addressed tech considerations reported by readers. ThePut up’sGeoffrey Fowler reported:

“Right here’s a security gap titanic sufficient to power a truck by,” reader Larry Whitted in Lodi, Calif., wrote last week.

As a buyer of Comcast’s Xfinity Cell cell phone carrier, Whitted says someone used to be ready to hijack his cell phone number, port it to a brand new memoir on one more community and commit identity fraud. The fraudster loaded Samsung Pay onto the new cell phone with Whitted’s credit card—and went to the Apple Store in Atlanta and supplied a pc, he stated.

The core of the topic: Comcast doesn’t protect its cell accounts with a particular PIN. (Comcast’s benefit function for switching carriers suggests here is to invent issues more straightforward: “We develop no longer require you to invent an memoir PIN, so that you simply develop no longer wish to provide that recordsdata to your new carrier.”) The default it makes use of as an different is…. 0000.

That Comcast benefit page used to be edited this week to exhaust away any references to the memoir PIN. The page says, “While you happen to contact your new carrier to switch your number, they will need your most popular address and Xfinity Mobile memoir number.”

Tale numbers are safe by password

This capability that of that 0000 PIN, getting a sufferer’s Xfinity Mobile memoir number used to be the predominant obstacle for attackers. A Comcast spokesperson informed Ars that this memoir number is within the market ultimate by logging into the Xfinity Mobile Web portal and is which capability that of this truth safe by a Comcast’s person’s password. Comcast informed Ars that it does no longer ship out paper funds for Xfinity Mobile and does no longer contain that memoir number in emails to prospects, removal two capacity ways in which attackers would possibly maybe well perchance also rep the memoir number.

Comcast indicated that the number-porting assault affected ultimate prospects who reused passwords across extra than one internet sites.

“We train this has ultimate affected prospects whose passwords would possibly maybe well perchance had been included in previous, non-Comcast linked breaches. We recommend that prospects use odd, stable passwords. In addition, prospects can further protect their Xfinity memoir by signing up for multi-assert authentication,” Comcast stated in an announcement supplied to Ars.

Comcast’s assertion additionally stated that “the faux porting of cell numbers is a successfully-acknowledged alternate trouble and no longer odd to Xfinity Mobile.” But Comcast would possibly maybe well perchance also have minimized the likelihood of assault, even for folks the usage of frail memoir passwords, by requiring prospects to raise a particular PIN when signing up for cell carrier.

Right here is what Comcast stated about adjustments or no longer it is made and can invent:

We’ve additionally applied a acknowledge that affords extra safeguards around our porting course of, and we’re working aggressively towards a PIN-primarily based acknowledge. We are reaching out to impacted prospects to drawl regret and work with them to tackle the assert. We exhaust this very seriously, and our fraud detection and prevention programs, insurance policies and procedures are continuously being reviewed, tested and complex.

What are the “extra safeguards” already applied in Comcast’s porting course of? A Comcast spokesperson declined to inform Ars, saying the firm doesn’t wish to provide potentially precious recordsdata to criminals. In a similar contrivance, Comcast supplied no tiny print on the timing and nature of its deliberate PIN-primarily based design.

One other buyer horror narrative

Comcast did scream that it had already applied its “extra safeguards” almost in the present day sooner than listening to from thePut up. The topic used to be beforehand described on February 24 by a buyer posting on the Xfinity neighborhood forum under the username jim5359.

“Any individual ported my Xfinity Mobile number without my authorization. They then veteran my cell number to interchange passwords on my PayPal and other accounts,” jim5359 wrote on the patron forum. “I spent 2 hours on the cell phone with a pleasant Xfinity Mobile agent who in fact wished to profit me. She informed me I desired to file a police file in bid for them to rep my number ported abet, which I did. I used to be informed the number would possibly maybe well perchance be ported abet within 72 hours. 72 hours handed and the number used to be no longer ported, so I known as again. Now I’m informed there is now not any longer a mode to rep the number ported abet since the person transferred the number to Straightforward Mobile and put apart a PIN on the number. So there is now not any longer a mode to port the number out of Straightforward Mobile without that PIN, even with a police file.”

“The actual same assert took build to me,” one more buyer wrote within the forum.

Jim5359 had requested the Comcast buyer uncover why there wasn’t a PIN to prevent the unauthorized number port.

“I used to be informed that Xfinity Mobile does no longer permit including a PIN to your number and the PIN is 0000 for all numbers,” jim5359 wrote. “So in fact, any individual who has your non-public recordsdata can switch your cell phone number out of Xfinity Mobile without your permission and with no need to provide a PIN. I used to be informed I would possibly maybe well perchance also rep a brand new cell phone number with Xfinity Mobile, nonetheless why would I attain that if someone clearly has my non-public recordsdata and clearly knows about this security flaw with Xfinity Mobile numbers?”

Jim5359 didn’t know the contrivance the attacker acquired the memoir password. “I’ve since modified my password and added 2-assert authentication. But every other cell firm has the added security of a PIN to prevent unauthorized porting,” jim5359 wrote.


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