Feeds

Researchers reveal NFC subway bonk-nonpayment scheme

Using Android phones to dodge fares

Choosing a cloud hosting partner with confidence

Transit systems around the world have begun turning to card-based "contactless" ticketing systems as an easy way to process fares. But according to security researchers, flaws in some ticketing schemes could allow savvy customers to bag themselves a permanent ticket to ride, using nothing more than an Android app and an NFC-enabled phone.

Speaking at the EUSecWest conference in Amsterdam last Thursday, Corey Benninger and Max Sobell of the Intrepidus Group revealed how weak security in certain tickets based on the MIFARE Ultralight chip could allow hackers to rewrite the data on the cards, potentially recharging them an infinite number of times.

Not every type of NFC-enabled transit ticket is vulnerable. The exploit only works on disposable, paper tickets that can be purchased for a specific number of trips. Permanent, plastic cards that offer more complicated fare schemes are not affected.

According to the researchers, the vulnerability lies in the fact that the tickets keep a count of the number of trips left on the card, but they do nothing to invalidate the card once the purchased number of trips is exhausted.

The Ultralight chip does include a few bits of storage that can only be written once and never again, which allows for the digital equivalent of punching a hole to the ticket to cancel it. But according to Benninger and Sobell, at least two US transit systems don't actually use this technique, and probably many more don't, either.

"We know a number of cities are looking to roll out contactless technology and hope we can bring light to this issue so that it is implemented correctly in the future," the researchers write in a blog post explaining the technical details of the hack.

The Intrepidus Group says it has actually developed an Android app that can exploit the flaw by copying the data from a brand-new ticket, then writing it back to the card when the purchased number of trips are used up. All that is required is an NFC-enabled phone, as demonstrated in the video below:

The researchers haven't released this version of the app – much to the relief of transit operators, no doubt – but they have released a version that can scan the data from a ticket to determine if the transit system in question is vulnerable. That version is available from the Google Play store.

The two vulnerable transit systems the Intrepidus Group has identified are the City of San Francisco's Muni rail and bus system and the Path train system, which shuttles passengers between New York City and various parts of the State of New Jersey.

The researchers say they have contacted both transit operators, explained the problem, and provided recommendations on how to fix the flaw. But although they say they contacted San Francisco Muni in December, your West Coast Reg hack can confirm that the Intrepidus Group's app still reports Muni tickets as vulnerable as of Monday.

The larger issue, the researchers say, is that the security features built into these disposable ticketing systems may be inadequate in a world where NFC-enabled smartphones are commonplace.

"One of the items we also raised in our talk is that full card emulation on smartphones is likely to happen soon," the researchers write. "When this does, it could cause a number of NFC based access control systems to be re-evaluated." ®

Internet Security Threat Report 2014

More from The Register

next story
FYI: OS X Yosemite's Spotlight tells Apple EVERYTHING you're looking for
It's on by default – didn't you read the small print?
Russian hackers exploit 'Sandworm' bug 'to spy on NATO, EU PCs'
Fix imminent from Microsoft for Vista, Server 2008, other stuff
Edward who? GCHQ boss dodges Snowden topic during last speech
UK spies would rather 'walk' than do 'mass surveillance'
Microsoft pulls another dodgy patch
Redmond makes a hash of hashing add-on
NOT OK GOOGLE: Android images can conceal code
It's been fixed, but hordes won't have applied the upgrade
'LulzSec leader Aush0k' found to be naughty boy not worthy of jail
15 months home detention leaves egg on feds' faces as they grab for more power
China is ALREADY spying on Apple iCloud users, claims watchdog
Attack harvests users' info at iPhone 6 launch
prev story

Whitepapers

Forging a new future with identity relationship management
Learn about ForgeRock's next generation IRM platform and how it is designed to empower CEOS's and enterprises to engage with consumers.
Why and how to choose the right cloud vendor
The benefits of cloud-based storage in your processes. Eliminate onsite, disk-based backup and archiving in favor of cloud-based data protection.
Three 1TB solid state scorchers up for grabs
Big SSDs can be expensive but think big and think free because you could be the lucky winner of one of three 1TB Samsung SSD 840 EVO drives that we’re giving away worth over £300 apiece.
Reg Reader Research: SaaS based Email and Office Productivity Tools
Read this Reg reader report which provides advice and guidance for SMBs towards the use of SaaS based email and Office productivity tools.
Security for virtualized datacentres
Legacy security solutions are inefficient due to the architectural differences between physical and virtual environments.