Tag Archives: bluetooth

Detecting Malicious Trackers

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2024/05/detecting-malicious-trackers.html

From Slashdot:

Apple and Google have launched a new industry standard called “Detecting Unwanted Location Trackers” to combat the misuse of Bluetooth trackers for stalking. Starting Monday, iPhone and Android users will receive alerts when an unknown Bluetooth device is detected moving with them. The move comes after numerous cases of trackers like Apple’s AirTags being used for malicious purposes.

Several Bluetooth tag companies have committed to making their future products compatible with the new standard. Apple and Google said they will continue collaborating with the Internet Engineering Task Force to further develop this technology and address the issue of unwanted tracking.

This seems like a good idea, but I worry about false alarms. If I am walking with a friend, will it alert if they have a Bluetooth tracking device in their pocket?

New Bluetooth Attack

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2023/12/new-bluetooth-attack.html

New attack breaks forward secrecy in Bluetooth.

Three news articles:

BLUFFS is a series of exploits targeting Bluetooth, aiming to break Bluetooth sessions’ forward and future secrecy, compromising the confidentiality of past and future communications between devices.

This is achieved by exploiting four flaws in the session key derivation process, two of which are new, to force the derivation of a short, thus weak and predictable session key (SKC).

Next, the attacker brute-forces the key, enabling them to decrypt past communication and decrypt or manipulate future communications.

The vulnerability has been around for at least a decade.

Crashing iPhones with a Flipper Zero

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2023/11/crashing-iphones-with-a-flipper-zero.html

The Flipper Zero is an incredibly versatile hacking device. Now it can be used to crash iPhones in its vicinity by sending them a never-ending stream of pop-ups.

These types of hacks have been possible for decades, but they require special equipment and a fair amount of expertise. The capabilities generally required expensive SDRs­—short for software-defined radios­—that, unlike traditional hardware-defined radios, use firmware and processors to digitally re-create radio signal transmissions and receptions. The $200 Flipper Zero isn’t an SDR in its own right, but as a software-controlled radio, it can do many of the same things at an affordable price and with a form factor that’s much more convenient than the previous generations of SDRs.

Hacking Gas Pumps via Bluetooth

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2023/10/hacking-gas-pumps-via-bluetooth.html

Turns out pumps at gas stations are controlled via Bluetooth, and that the connections are insecure. No details in the article, but it seems that it’s easy to take control of the pump and have it dispense gas without requiring payment.

It’s a complicated crime to monetize, though. You need to sell access to the gas pump to others.

EDITED TO ADD (10/13): Reader Jeff Hall says that story is not accurate, and that the gas pumps do not have a Bluetooth connection.

Tracking People via Bluetooth on Their Phones

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2022/06/tracking-people-via-bluetooth-on-their-phones.html

We’ve always known that phones—and the people carrying them—can be uniquely identified from their Bluetooth signatures, and that we need security techniques to prevent that. This new research shows that that’s not enough.

Computer scientists at the University of California San Diego proved in a study published May 24 that minute imperfections in phones caused during manufacturing create a unique Bluetooth beacon, one that establishes a digital signature or fingerprint distinct from any other device. Though phones’ Bluetooth uses cryptographic technology that limits trackability, using a radio receiver, these distortions in the Bluetooth signal can be discerned to track individual devices.

[…]

The study’s scientists conducted tests to show whether multiple phones being in one place could disrupt their ability to track individual signals. Results in an initial experiment showed they managed to discern individual signals for 40% of 162 devices in public. Another, scaled-up experiment showed they could discern 47% of 647 devices in a public hallway across two days.

The tracking range depends on device and the environment, and it could be several hundred feet, but in a crowded location it might only be 10 or so feet. Scientists were able to follow a volunteer’s signal as they went to and from their house. Certain environmental factors can disrupt a Bluetooth signal, including changes in environment temperature, and some devices send signals with more power and range than others.

One might say “well, I’ll just keep Bluetooth turned off when not in use,” but the researchers said they found that some devices, especially iPhones, don’t actually turn off Bluetooth unless a user goes directly into settings to turn off the signal. Most people might not even realize their Bluetooth is being constantly emitted by many smart devices.

Bluetooth Flaw Allows Remote Unlocking of Digital Locks

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2022/05/bluetooth-flaw-allows-remote-unlocking-of-digital-locks.html

Locks that use Bluetooth Low Energy to authenticate keys are vulnerable to remote unlocking. The research focused on Teslas, but the exploit is generalizable.

In a video shared with Reuters, NCC Group researcher Sultan Qasim Khan was able to open and then drive a Tesla using a small relay device attached to a laptop which bridged a large gap between the Tesla and the Tesla owner’s phone.

“This proves that any product relying on a trusted BLE connection is vulnerable to attacks even from the other side of the world,” the UK-based firm said in a statement, referring to the Bluetooth Low Energy (BLE) protocol—technology used in millions of cars and smart locks which automatically open when in close proximity to an authorised device.

Although Khan demonstrated the hack on a 2021 Tesla Model Y, NCC Group said any smart locks using BLE technology, including residential smart locks, could be unlocked in the same way.

Another news article.

iPhone Malware that Operates Even When the Phone Is Turned Off

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2022/05/iphone-malware-that-operates-even-when-the-phone-is-turned-off.html

Researchers have demonstrated iPhone malware that works even when the phone is fully shut down.

t turns out that the iPhone’s Bluetooth chip­ — which is key to making features like Find My work­ — has no mechanism for digitally signing or even encrypting the firmware it runs. Academics at Germany’s Technical University of Darmstadt figured out how to exploit this lack of hardening to run malicious firmware that allows the attacker to track the phone’s location or run new features when the device is turned off.

[…]

The research is the first — or at least among the first — to study the risk posed by chips running in low-power mode. Not to be confused with iOS’s low-power mode for conserving battery life, the low-power mode (LPM) in this research allows chips responsible for near-field communication, ultra wideband, and Bluetooth to run in a special mode that can remain on for 24 hours after a device is turned off.

The research is fascinating, but the attack isn’t really feasible. It requires a jailbroken phone, which is hard to pull off in an adversarial setting.

Slashdot thread.

Cheating on Tests

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2021/10/cheating-on-tests.html

Interesting story of test-takers in India using Bluetooth-connected flip-flops to communicate with accomplices while taking a test.

What’s interesting is how this cheating was discovered. It’s not that someone noticed the communication devices. It’s that the proctors noticed that cheating test takers were acting hinky.

Tracking People by their MAC Addresses

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2021/09/tracking-people-by-their-mac-addresses.html

Yet another article on the privacy risks of static MAC addresses and always-on Bluetooth connections. This one is about wireless headphones.

The good news is that product vendors are fixing this:

Several of the headphones which could be tracked over time are for sale in electronics stores, but according to two of the manufacturers NRK have spoken to, these models are being phased out.

“The products in your line-up, Elite Active 65t, Elite 65e and Evolve 75e, will be going out of production before long and newer versions have already been launched with randomized MAC addresses. We have a lot of focus on privacy by design and we continuously work with the available security measures on the market,” head of PR at Jabra, Claus Fonnesbech says.

“To run Bluetooth Classic we, and all other vendors, are required to have static addresses and you will find that in older products,” Fonnesbech says.

Jens Bjørnkjær Gamborg, head of communications at Bang & Olufsen, says that “this is products that were launched several years ago.”

“All products launched after 2019 randomize their MAC-addresses on a frequent basis as it has become the market standard to do so,” Gamborg says.

EDITED TO ADD (9/13): It’s not enough to randomly change MAC addresses. Any other plaintext identifiers need to be changed at the same time.

New Bluetooth Vulnerability

Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2020/09/new-bluetooth-vulnerability.html

There’s a new unpatched Bluetooth vulnerability:

The issue is with a protocol called Cross-Transport Key Derivation (or CTKD, for short). When, say, an iPhone is getting ready to pair up with Bluetooth-powered device, CTKD’s role is to set up two separate authentication keys for that phone: one for a “Bluetooth Low Energy” device, and one for a device using what’s known as the “Basic Rate/Enhanced Data Rate” standard. Different devices require different amounts of data — and battery power — from a phone. Being able to toggle between the standards needed for Bluetooth devices that take a ton of data (like a Chromecast), and those that require a bit less (like a smartwatch) is more efficient. Incidentally, it might also be less secure.

According to the researchers, if a phone supports both of those standards but doesn’t require some sort of authentication or permission on the user’s end, a hackery sort who’s within Bluetooth range can use its CTKD connection to derive its own competing key. With that connection, according to the researchers, this sort of erzatz authentication can also allow bad actors to weaken the encryption that these keys use in the first place — which can open its owner up to more attacks further down the road, or perform “man in the middle” style attacks that snoop on unprotected data being sent by the phone’s apps and services.

Another article:

Patches are not immediately available at the time of writing. The only way to protect against BLURtooth attacks is to control the environment in which Bluetooth devices are paired, in order to prevent man-in-the-middle attacks, or pairings with rogue devices carried out via social engineering (tricking the human operator).

However, patches are expected to be available at one point. When they’ll be, they’ll most likely be integrated as firmware or operating system updates for Bluetooth capable devices.

The timeline for these updates is, for the moment, unclear, as device vendors and OS makers usually work on different timelines, and some may not prioritize security patches as others. The number of vulnerable devices is also unclear and hard to quantify.

Many Bluetooth devices can’t be patched.

Final note: this seems to be another example of simultaneous discovery:

According to the Bluetooth SIG, the BLURtooth attack was discovered independently by two groups of academics from the École Polytechnique Fédérale de Lausanne (EPFL) and Purdue University.