Entries Tagged "AT&T"

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AT&T's iPad Security Breach

I didn’t write about the recent security breach that disclosed tens of thousands of e-mail addresses and ICC-IDs of iPad users because, well, there was nothing terribly interesting about it. It was yet another web security breach.

Right after the incident, though, I was being interviewed by a reporter that wanted to know what the ramifications of the breach were. He specifically wanted to know if anything could be done with those ICC-IDs, and if the disclosure of that information was worse than people thought. He didn’t like the answer I gave him, which is that no one knows yet: that it’s too early to know the full effects of that information disclosure, and that both the good guys and the bad guys would be figuring it out in the coming weeks. And, that it’s likely that there were further security implications of the breach.

Seems like there were:

The problem is that ICC-IDs—unique serial numbers that identify each SIM card—can often be converted into IMSIs. While the ICC-ID is nonsecret—it’s often found printed on the boxes of cellphone/SIM bundles—the IMSI is somewhat secret. In theory, knowing an ICC-ID shouldn’t be enough to determine an IMSI. The phone companies do need to know which IMSI corresponds to which ICC-ID, but this should be done by looking up the values in a big database.

In practice, however, many phone companies simply calculate the IMSI from the ICC-ID. This calculation is often very simple indeed, being little more complex than “combine this hard-coded value with the last nine digits of the ICC-ID.” So while the leakage of AT&T’s customers’ ICC-IDs should be harmless, in practice, it could reveal a secret ID.

What can be done with that secret ID? Quite a lot, it turns out. The IMSI is sent by the phone to the network when first signing on to the network; it’s used by the network to figure out which call should be routed where. With someone else’s IMSI, an attacker can determine the person’s name and phone number, and even track his or her position. It also opens the door to active attacks—creating fake cell towers that a victim’s phone will connect to, enabling every call and text message to be eavesdropped.

More to come, I’m sure.

And that’s really the point: we all want to know—right away—the effects of a security vulnerability, but often we don’t and can’t. It takes time before the full effects are known, sometimes a lot of time.

And in related news, the image redaction that went along with some of the breach reporting wasn’t very good.

Posted on June 21, 2010 at 5:27 AM • View Comments

Call Forwarding Credit Card Scam

This is impressive:

A fraudster contacts an AT&T service rep and says he works at a pizza parlor and that the phone is having trouble. Until things get fixed, he requests that all incoming calls be forwarded to another number, which he provides.

Pizza orders are thus routed by AT&T to the fraudster’s line. When a call comes in, the fraudster pretends to take the customer’s order but says payment must be made in advance by credit card.

The unsuspecting customer gives his or her card number and expiration date, and before you can say “extra cheese,” the fraudster is ready to go on an Internet shopping spree using someone else’s money.

Those of us who know security have been telling people not to trust incoming phone calls—that you should call the company if you are going to divulge personal information to them. Seems like that advice isn’t foolproof.

The problem is the phone company, of course. They’re forwarding calls based on an unauthenticated request. AT&T doesn’t really want to talk about details:

He was reluctant to discuss the steps AT&T has taken to improve its call-forwarding system so this sort of thing doesn’t happen again. What, for example, is to prevent someone from convincing AT&T to forward all calls to a local flower store or some other business that takes orders by phone?

“We had some guidelines in place that we believe were effective,” Britton said. “Now we have extra precautions.”

It seems to me that AT&T would solve this problem more quickly if it were liable. Shouldn’t a pizza customer who has been scammed be allowed to sue AT&T? After all, the phone company didn’t route the customer’s calls properly. Does the credit card company have a basis for a suit? Certainly the pizza parlor does, but the effects of AT&T’s sloppy authentication are much greater than a few missed pizza orders.

Posted on August 21, 2006 at 1:35 PM • View Comments

AT&T Rewrites its Privacy Policy

AT&T has a new privacy policy, and if you are its customer you have no choice but to accept it.

The new policy says that AT&T—not customers—owns customers’ confidential info and can use it “to protect its legitimate business interests, safeguard others, or respond to legal process.”

The policy also indicates that AT&T will track the viewing habits of customers of its new video service—something that cable and satellite providers are prohibited from doing.

Moreover, AT&T (formerly known as SBC) is requiring customers to agree to its updated privacy policy as a condition for service—a new move that legal experts say will reduce customers’ recourse for any future data sharing with government authorities or others.

EDITED TO ADD (6/27): User Friendly on the issue.

Posted on June 23, 2006 at 6:03 AM • View Comments

AT&T Assisting NSA Surveillance

Interesting details emerging from EFF’s lawsuit:

According to a statement released by Klein’s attorney, an NSA agent showed up at the San Francisco switching center in 2002 to interview a management-level technician for a special job. In January 2003, Klein observed a new room being built adjacent to the room housing AT&T’s #4ESS switching equipment, which is responsible for routing long distance and international calls.

“I learned that the person whom the NSA interviewed for the secret job was the person working to install equipment in this room,” Klein wrote. “The regular technician work force was not allowed in the room.”

Klein’s job eventually included connecting internet circuits to a splitting cabinet that led to the secret room. During the course of that work, he learned from a co-worker that similar cabinets were being installed in other cities, including Seattle, San Jose, Los Angeles and San Diego.

“While doing my job, I learned that fiber optic cables from the secret room were tapping into the Worldnet (AT&T’s internet service) circuits by splitting off a portion of the light signal,” Klein wrote.

The split circuits included traffic from peering links connecting to other internet backbone providers, meaning that AT&T was also diverting traffic routed from its network to or from other domestic and international providers, according to Klein’s statement.

The secret room also included data-mining equipment called a Narus STA 6400, “known to be used particularly by government intelligence agencies because of its ability to sift through large amounts of data looking for preprogrammed targets,” according to Klein’s statement.

Narus, whose website touts AT&T as a client, sells software to help internet service providers and telecoms monitor and manage their networks, look for intrusions, and wiretap phone calls as mandated by federal law.

More about what the Narus box can do.

EDITED TO ADD (4/14): More about Narus.

Posted on April 14, 2006 at 7:58 AM • View Comments

AT&T's 1.9-Trillion-Call Database

This whole article is worth reading, but I found this tidbit particularly interesting:

He was alluding to databases maintained at an AT&T data center in Kansas, which now contain electronic records of 1.92 trillion telephone calls, going back decades. The Electronic Frontier Foundation, a digital-rights advocacy group, has asserted in a lawsuit that the AT&T Daytona system, a giant storehouse of calling records and Internet message routing information, was the foundation of the N.S.A.’s effort to mine telephone records without a warrant.

An AT&T spokeswoman said the company would not comment on the claim, or generally on matters of national security or customer privacy.

But the mining of the databases in other law enforcement investigations is well established, with documented results. One application of the database technology, called Security Call Analysis and Monitoring Platform, or Scamp, offers access to about nine weeks of calling information. It currently handles about 70,000 queries a month from fraud and law enforcement investigators, according to AT&T documents.

A former AT&T official who had detailed knowledge of the call-record database said the Daytona system takes great care to make certain that anyone using the database – whether AT&T employee or law enforcement official with a subpoena – sees only information he or she is authorized to see, and that an audit trail keeps track of all users. Such information is frequently used to build models of suspects’ social networks.

The official, speaking on condition of anonymity because he was discussing sensitive corporate matters, said every telephone call generated a record: number called, time of call, duration of call, billing category and other details. While the database does not contain such billing data as names, addresses and credit card numbers, those records are in a linked database that can be tapped by authorized users.

New calls are entered into the database immediately after they end, the official said, adding, “I would characterize it as near real time.”

According to a current AT&T employee, whose identity is being withheld to avoid jeopardizing his job, the mining of the AT&T databases had a notable success in helping investigators find the perpetrators of what was known as the Moldovan porn scam.

In 1997 a shadowy group in Moldova, a former Soviet republic, was tricking Internet users by enticing them to a pornography Web site that would download a piece of software that disconnected the computer user from his local telephone line and redialed a costly 900 number in Moldova.

While another long-distance carrier simply cut off the entire nation of Moldova from its network, AT&T and the Moldovan authorities were able to mine the database to track the culprits.

Posted on March 3, 2006 at 11:45 AM • View Comments

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Sidebar photo of Bruce Schneier by Joe MacInnis.