A poor scheme for logging in to the Verizon Wireless customer support Web site using a simple session ID number makes it easy for a malicious party to hijack another user's session and examine his wireless phone records.
An example URL shows how simple it would be to manipulate the session ID:
It's believed that the session ID's are assigned sequentially, so it would be short work for someone to develop a little brute-force progie to exploit them. Even guessing would probably work reasonably well for someone with time on his hands, since the scheme is appallingly simple.
The flaw was discovered and reported by software engineer Marc Slemko, who contacted the company two weeks ago but heard nothing in reply. So he posted the information to the BugTraq mailing list this past weekend, hoping to get some action from Verizon techies.
The more public approach seems to have worked like a charm. The company is now conducting an investigation into the validity and scope of the problem, Verizon Executive Director of Corporate Communications Brian Wood told us.
In the mean time, until the hole is bunged, Slemko recommends that customers not access the Web site.
"Cell phone bills....contain names, addresses, and a complete record of calls placed and received, along with the approximate location the user was when the call was made," Slemko observes in his BugTraq post. "I'm sure I'm not alone in expecting my provider to provide a reasonable level of privacy for this data."
The contact buffer
We've been wondering why Verizon needed prodding into action on such an important matter. Apparently, poor internal communications is to blame. As of Tuesday, the company was unable to locate Slemko's memo or any record of his original contact.
"I did not even bother phoning, since trying to explain a problem of a technical nature over the phone to first and second and third etc. tier customer service reps is just a pointless waste of time that I don't have to spare," Slemko told us.
"I wouldn't doubt that it didn't make its way to the right people. Verizon is more forceful than most companies in making it very difficult to get in touch with anyone useful. I submitted a detailed description -- along with a note-to-incompetents that if they don't understand what I'm talking about, they had better escalate it -- by using their on-line 'contact us' procedures."
So it would appear that his memo went directly into the great customer-service slush pile, and languished.
We have to agree with Slemko's characterization of contacting Verizon beyond the customer-service-drone level. We experienced a similar problem in researching this story, which (having a wide experience with this sort of thing) we quickly solved by grabbing a company press release off one of the wire services and approaching a contact named in it.
Alternatively, we could have done an Edgar search and got the corporate switchboard number. But the Verizon Wireless Web site offered nothing but a mass-email account, and a toll-free customer-service number, neither of which would have accommodated our level of patience.
We realize that this sort of access buffering is meant to insulate busy executives from repeated, meaningless contacts with the self-interested and the deranged, but in this case its inherent downside has been nicely illustrated. ®