Entries Tagged "hardware"

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Levels of Assurance for DoD Microelectronics

The NSA has has published criteria for evaluating levels of assurance required for DoD microelectronics.

The introductory report in a DoD microelectronics series outlines the process for determining levels of hardware assurance for systems and custom microelectronic components, which include application-specific integrated circuits (ASICs), field programmable gate arrays (FPGAs) and other devices containing reprogrammable digital logic.

The levels of hardware assurance are determined by the national impact caused by failure or subversion of the top-level system and the criticality of the component to that top-level system. The guidance helps programs acquire a better understanding of their system and components so that they can effectively mitigate against threats.

The report was published last month, but I only just noticed it.

Posted on August 29, 2022 at 9:30 AMView Comments

Security and Cheap Complexity

I’ve been saying that complexity is the worst enemy of security for a long time now. (Here’s me in 1999.) And it’s been true for a long time.

In 2018, Thomas Dullien of Google’s Project Zero talked about “cheap complexity.” Andrew Appel summarizes:

The anomaly of cheap complexity. For most of human history, a more complex device was more expensive to build than a simpler device. This is not the case in modern computing. It is often more cost-effective to take a very complicated device, and make it simulate simplicity, than to make a simpler device. This is because of economies of scale: complex general-purpose CPUs are cheap. On the other hand, custom-designed, simpler, application-specific devices, which could in principle be much more secure, are very expensive.

This is driven by two fundamental principles in computing: Universal computation, meaning that any computer can simulate any other; and Moore’s law, predicting that each year the number of transistors on a chip will grow exponentially. ARM Cortex-M0 CPUs cost pennies, though they are more powerful than some supercomputers of the 20th century.

The same is true in the software layers. A (huge and complex) general-purpose operating system is free, but a simpler, custom-designed, perhaps more secure OS would be very expensive to build. Or as Dullien asks, “How did this research code someone wrote in two weeks 20 years ago end up in a billion devices?”

This is correct. Today, it’s easier to build complex systems than it is to build simple ones. As recently as twenty years ago, if you wanted to build a refrigerator you would create custom refrigerator controller hardware and embedded software. Today, you just grab some standard microcontroller off the shelf and write a software application for it. And that microcontroller already comes with an IP stack, a microphone, a video port, Bluetooth, and a whole lot more. And since those features are there, engineers use them.

Posted on August 26, 2022 at 6:54 AMView Comments

M1 Chip Vulnerability

This is a new vulnerability against Apple’s M1 chip. Researchers say that it is unpatchable.

Researchers from MIT’s Computer Science and Artificial Intelligence Laboratory, however, have created a novel hardware attack, which combines memory corruption and speculative execution attacks to sidestep the security feature. The attack shows that pointer authentication can be defeated without leaving a trace, and as it utilizes a hardware mechanism, no software patch can fix it.

The attack, appropriately called “Pacman,” works by “guessing” a pointer authentication code (PAC), a cryptographic signature that confirms that an app hasn’t been maliciously altered. This is done using speculative execution—a technique used by modern computer processors to speed up performance by speculatively guessing various lines of computation—to leak PAC verification results, while a hardware side-channel reveals whether or not the guess was correct.

What’s more, since there are only so many possible values for the PAC, the researchers found that it’s possible to try them all to find the right one.

It’s not obvious how to exploit this vulnerability in the wild, so I’m unsure how important this is. Also, I don’t know if it also applies to Apple’s new M2 chip.

Research paper. Another news article.

Posted on June 15, 2022 at 6:05 AMView Comments

Testing Faraday Cages

Matt Blaze tested a variety of Faraday cages for phones, both commercial and homemade.

The bottom line:

A quick and likely reliable “go/no go test” can be done with an Apple AirTag and an iPhone: drop the AirTag in the bag under test, and see if the phone can locate it and activate its alarm (beware of caching in the FindMy app when doing this).

This test won’t tell you the exact attenuation level, of course, but it will tell you if the attenuation is sufficient for most practical purposes. It can also detect whether an otherwise good bag has been damaged and compromised.

At least in the frequency ranges I tested, two commercial Faraday pouches (the EDEC OffGrid and Mission Darkness Window pouches) yielded excellent performance sufficient to provide assurance of signal isolation under most real-world circumstances. None of the makeshift solutions consistently did nearly as well, although aluminum foil can, under ideal circumstances (that are difficult to replicate) sometimes provide comparable levels of attenuation.

Posted on December 3, 2021 at 6:13 AMView Comments

New Rowhammer Technique

Rowhammer is an attack technique involving accessing—that’s “hammering”—rows of bits in memory, millions of times per second, with the intent of causing bits in neighboring rows to flip. This is a side-channel attack, and the result can be all sorts of mayhem.

Well, there is a new enhancement:

All previous Rowhammer attacks have hammered rows with uniform patterns, such as single-sided, double-sided, or n-sided. In all three cases, these “aggressor” rows—meaning those that cause bitflips in nearby “victim” rows—are accessed the same number of times.

Research published on Monday presented a new Rowhammer technique. It uses non-uniform patterns that access two or more aggressor rows with different frequencies. The result: all 40 of the randomly selected DIMMs in a test pool experienced bitflips, up from 13 out of 42 chips tested in previous work from the same researchers.

[…]

The non-uniform patterns work against Target Row Refresh. Abbreviated as TRR, the mitigation works differently from vendor to vendor but generally tracks the number of times a row is accessed and recharges neighboring victim rows when there are signs of abuse. The neutering of this defense puts further pressure on chipmakers to mitigate a class of attacks that many people thought more recent types of memory chips were resistant to.

Posted on November 19, 2021 at 8:31 AMView Comments

New Spectre-Like Attacks

There’s new research that demonstrates security vulnerabilities in all of the AMD and Intel chips with micro-op caches, including the ones that were specifically engineered to be resistant to the Spectre/Meltdown attacks of three years ago.

Details:

The new line of attacks exploits the micro-op cache: an on-chip structure that speeds up computing by storing simple commands and allowing the processor to fetch them quickly and early in the speculative execution process, as the team explains in a writeup from the University of Virginia. Even though the processor quickly realizes its mistake and does a U-turn to go down the right path, attackers can get at the private data while the processor is still heading in the wrong direction.

It seems really difficult to exploit these vulnerabilities. We’ll need some more analysis before we understand what we have to patch and how.

More news.

Posted on May 5, 2021 at 10:35 AMView Comments

Router Security

This report is six months old, and I don’t know anything about the organization that produced it, but it has some alarming data about router security.

Conclusion: Our analysis showed that Linux is the most used OS running on more than 90% of the devices. However, many routers are powered by very old versions of Linux. Most devices are still powered with a 2.6 Linux kernel, which is no longer maintained for many years. This leads to a high number of critical and high severity CVEs affecting these devices.

Since Linux is the most used OS, exploit mitigation techniques could be enabled very easily. Anyhow, they are used quite rarely by most vendors except the NX feature.

A published private key provides no security at all. Nonetheless, all but one vendor spread several private keys in almost all firmware images.

Mirai used hard-coded login credentials to infect thousands of embedded devices in the last years. However, hard-coded credentials can be found in many of the devices and some of them are well known or at least easy crackable.

However, we can tell for sure that the vendors prioritize security differently. AVM does better job than the other vendors regarding most aspects. ASUS and Netgear do a better job in some aspects than D-Link, Linksys, TP-Link and Zyxel.

Additionally, our evaluation showed that large scale automated security analysis of embedded devices is possible today utilizing just open source software. To sum it up, our analysis shows that there is no router without flaws and there is no vendor who does a perfect job regarding all security aspects. Much more effort is needed to make home routers as secure as current desktop of server systems.

One comment on the report:

One-third ship with Linux kernel version 2.6.36 was released in October 2010. You can walk into a store today and buy a brand new router powered by software that’s almost 10 years out of date! This outdated version of the Linux kernel has 233 known security vulnerabilities registered in the Common Vulnerability and Exposures (CVE) database. The average router contains 26 critically-rated security vulnerabilities, according to the study.

We know the reasons for this. Most routers are designed offshore, by third parties, and then private labeled and sold by the vendors you’ve heard of. Engineering teams come together, design and build the router, and then disperse. There’s often no one around to write patches, and most of the time router firmware isn’t even patchable. The way to update your home router is to throw it away and buy a new one.

And this paper demonstrates that even the new ones aren’t likely to be secure.

Posted on February 19, 2021 at 6:00 AMView Comments

Cloning Google Titan 2FA keys

This is a clever side-channel attack:

The cloning works by using a hot air gun and a scalpel to remove the plastic key casing and expose the NXP A700X chip, which acts as a secure element that stores the cryptographic secrets. Next, an attacker connects the chip to hardware and software that take measurements as the key is being used to authenticate on an existing account. Once the measurement-taking is finished, the attacker seals the chip in a new casing and returns it to the victim.

Extracting and later resealing the chip takes about four hours. It takes another six hours to take measurements for each account the attacker wants to hack. In other words, the process would take 10 hours to clone the key for a single account, 16 hours to clone a key for two accounts, and 22 hours for three accounts.

By observing the local electromagnetic radiations as the chip generates the digital signatures, the researchers exploit a side channel vulnerability in the NXP chip. The exploit allows an attacker to obtain the long-term elliptic curve digital signal algorithm private key designated for a given account. With the crypto key in hand, the attacker can then create her own key, which will work for each account she targeted.

The attack isn’t free, but it’s not expensive either:

A hacker would first have to steal a target’s account password and also gain covert possession of the physical key for as many as 10 hours. The cloning also requires up to $12,000 worth of equipment and custom software, plus an advanced background in electrical engineering and cryptography. That means the key cloning—­were it ever to happen in the wild—­would likely be done only by a nation-state pursuing its highest-value targets.

That last line about “nation-state pursuing its highest-value targets” is just not true. There are many other situations where this attack is feasible.

Note that the attack isn’t against the Google system specifically. It exploits a side-channel attack in the NXP chip. Which means that other systems are probably vulnerable:

While the researchers performed their attack on the Google Titan, they believe that other hardware that uses the A700X, or chips based on the A700X, may also be vulnerable. If true, that would include Yubico’s YubiKey NEO and several 2FA keys made by Feitian.

Posted on January 12, 2021 at 6:16 AMView Comments

Backdoor in Zyxel Firewalls and Gateways

This is bad:

More than 100,000 Zyxel firewalls, VPN gateways, and access point controllers contain a hardcoded admin-level backdoor account that can grant attackers root access to devices via either the SSH interface or the web administration panel.

[…]

Installing patches removes the backdoor account, which, according to Eye Control researchers, uses the “zyfwp” username and the “PrOw!aN_fXp” password.

“The plaintext password was visible in one of the binaries on the system,” the Dutch researchers said in a report published before the Christmas 2020 holiday.

Posted on January 6, 2021 at 5:44 AMView Comments

Swiss-Swedish Diplomatic Row Over Crypto AG

Previously I have written about the Swedish-owned Swiss-based cryptographic hardware company: Crypto AG. It was a CIA-owned Cold War operation for decades. Today it is called Crypto International, still based in Switzerland but owned by a Swedish company.

It’s back in the news:

Late last week, Swedish Foreign Minister Ann Linde said she had canceled a meeting with her Swiss counterpart Ignazio Cassis slated for this month after Switzerland placed an export ban on Crypto International, a Swiss-based and Swedish-owned cybersecurity company.

The ban was imposed while Swiss authorities examine long-running and explosive claims that a previous incarnation of Crypto International, Crypto AG, was little more than a front for U.S. intelligence-gathering during the Cold War.

Linde said the Swiss ban was stopping “goods”—which experts suggest could include cybersecurity upgrades or other IT support needed by Swedish state agencies—from reaching Sweden.

She told public broadcaster SVT that the meeting with Cassis was “not appropriate right now until we have fully understood the Swiss actions.”

EDITED TO ADD (10/13): Lots of information on Crypto AG.

Posted on October 6, 2020 at 6:11 AMView Comments

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Sidebar photo of Bruce Schneier by Joe MacInnis.