Entries Tagged "hardware"

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Adding a Hardware Backdoor to a Networked Computer

Interesting proof of concept:

At the CS3sthlm security conference later this month, security researcher Monta Elkins will show how he created a proof-of-concept version of that hardware hack in his basement. He intends to demonstrate just how easily spies, criminals, or saboteurs with even minimal skills, working on a shoestring budget, can plant a chip in enterprise IT equipment to offer themselves stealthy backdoor access…. With only a $150 hot-air soldering tool, a $40 microscope, and some $2 chips ordered online, Elkins was able to alter a Cisco firewall in a way that he says most IT admins likely wouldn’t notice, yet would give a remote attacker deep control.

Posted on October 18, 2019 at 5:54 AMView Comments

Hacking Hardware Security Modules

Security researchers Gabriel Campana and Jean-Baptiste Bédrune are giving a hardware security module (HSM) talk at BlackHat in August:

This highly technical presentation targets an HSM manufactured by a vendor whose solutions are usually found in major banks and large cloud service providers. It will demonstrate several attack paths, some of them allowing unauthenticated attackers to take full control of the HSM. The presented attacks allow retrieving all HSM secrets remotely, including cryptographic keys and administrator credentials. Finally, we exploit a cryptographic bug in the firmware signature verification to upload a modified firmware to the HSM. This firmware includes a persistent backdoor that survives a firmware update.

They have an academic paper in French, and a presentation of the work. Here’s a summary in English.

There were plenty of technical challenges to solve along the way, in what was clearly a thorough and professional piece of vulnerability research:

  1. They started by using legitimate SDK access to their test HSM to upload a firmware module that would give them a shell inside the HSM. Note that this SDK access was used to discover the attacks, but is not necessary to exploit them.
  2. They then used the shell to run a fuzzer on the internal implementation of PKCS#11 commands to find reliable, exploitable buffer overflows.
  3. They checked they could exploit these buffer overflows from outside the HSM, i.e. by just calling the PKCS#11 driver from the host machine
  4. They then wrote a payload that would override access control and, via another issue in the HSM, allow them to upload arbitrary (unsigned) firmware. It’s important to note that this backdoor is persistent ­ a subsequent update will not fix it.
  5. They then wrote a module that would dump all the HSM secrets, and uploaded it to the HSM.

Posted on June 20, 2019 at 6:56 AMView Comments

Thangrycat: A Serious Cisco Vulnerability


Thangrycat is caused by a series of hardware design flaws within Cisco’s Trust Anchor module. First commercially introduced in 2013, Cisco Trust Anchor module (TAm) is a proprietary hardware security module used in a wide range of Cisco products, including enterprise routers, switches and firewalls. TAm is the root of trust that underpins all other Cisco security and trustworthy computing mechanisms in these devices. Thangrycat allows an attacker to make persistent modification to the Trust Anchor module via FPGA bitstream modification, thereby defeating the secure boot process and invalidating Cisco’s chain of trust at its root. While the flaws are based in hardware, Thangrycat can be exploited remotely without any need for physical access. Since the flaws reside within the hardware design, it is unlikely that any software security patch will fully resolve the fundamental security vulnerability.

From a news article:

Thrangrycat is awful for two reasons. First, if a hacker exploits this weakness, they can do whatever they want to your routers. Second, the attack can happen remotely ­ it’s a software vulnerability. But the fix can only be applied at the hardware level. Like, physical router by physical router. In person. Yeesh.

That said, Thrangrycat only works once you have administrative access to the device. You need a two-step attack in order to get Thrangrycat working. Attack #1 gets you remote administrative access, Attack #2 is Thrangrycat. Attack #2 can’t happen without Attack #1. Cisco can protect you from Attack #1 by sending out a software update. If your I.T. people have your systems well secured and are applying updates and patches consistently and you’re not a regular target of nation-state actors, you’re relatively safe from Attack #1, and therefore, pretty safe from Thrangrycat.

Unfortunately, Attack #1 is a garden variety vulnerability. Many systems don’t even have administrative access configured correctly. There’s opportunity for Thrangrycat to be exploited.

And from Boing Boing:

Thangrycat relies on attackers being able to run processes as the system’s administrator, and Red Balloon, the security firm that disclosed the vulnerability, also revealed a defect that allows attackers to run code as admin.

It’s tempting to dismiss the attack on the trusted computing module as a ho-hum flourish: after all, once an attacker has root on your system, all bets are off. But the promise of trusted computing is that computers will be able to detect and undo this kind of compromise, by using a separate, isolated computer to investigate and report on the state of the main system (Huang and Snowden call this an introspection engine). Once this system is compromised, it can be forced to give false reports on the state of the system: for example, it might report that its OS has been successfully updated to patch a vulnerability when really the update has just been thrown away.

As Charlie Warzel and Sarah Jeong discuss in the New York Times, this is an attack that can be executed remotely, but can only be detected by someone physically in the presence of the affected system (and only then after a very careful inspection, and there may still be no way to do anything about it apart from replacing the system or at least the compromised component).

Posted on May 23, 2019 at 11:52 AMView Comments

Another Intel Chip Flaw

Remember the Spectre and Meltdown attacks from last year? They were a new class of attacks against complex CPUs, finding subliminal channels in optimization techniques that allow hackers to steal information. Since their discovery, researchers have found additional similar vulnerabilities.

A whole bunch more have just been discovered.

I don’t think we’re finished yet. A year and a half ago I wrote: “But more are coming, and they’ll be worse. 2018 will be the year of microprocessor vulnerabilities, and it’s going to be a wild ride.” I think more are still coming.

EDITED TO ADD (6/13): A mathematical analysis of the problem that claims we’ll never completely fix this class of problems.

Posted on May 16, 2019 at 9:28 AMView Comments

DARPA Is Developing an Open-Source Voting System

This sounds like a good development:

…a new $10 million contract the Defense Department’s Defense Advanced Research Projects Agency (DARPA) has launched to design and build a secure voting system that it hopes will be impervious to hacking.

The first-of-its-kind system will be designed by an Oregon-based firm called Galois, a longtime government contractor with experience in designing secure and verifiable systems. The system will use fully open source voting software, instead of the closed, proprietary software currently used in the vast majority of voting machines, which no one outside of voting machine testing labs can examine. More importantly, it will be built on secure open source hardware, made from special secure designs and techniques developed over the last year as part of a special program at DARPA. The voting system will also be designed to create fully verifiable and transparent results so that voters don’t have to blindly trust that the machines and election officials delivered correct results.

But DARPA and Galois won’t be asking people to blindly trust that their voting systems are secure — as voting machine vendors currently do. Instead they’ll be publishing source code for the software online and bring prototypes of the systems to the Def Con Voting Village this summer and next, so that hackers and researchers will be able to freely examine the systems themselves and conduct penetration tests to gauge their security. They’ll also be working with a number of university teams over the next year to have them examine the systems in formal test environments.

Posted on March 14, 2019 at 1:20 PMView Comments

Banks Attacked through Malicious Hardware Connected to the Local Network

Kaspersky is reporting on a series of bank hacks — called DarkVishnya — perpetrated through malicious hardware being surreptitiously installed into the target network:

In 2017-2018, Kaspersky Lab specialists were invited to research a series of cybertheft incidents. Each attack had a common springboard: an unknown device directly connected to the company’s local network. In some cases, it was the central office, in others a regional office, sometimes located in another country. At least eight banks in Eastern Europe were the targets of the attacks (collectively nicknamed DarkVishnya), which caused damage estimated in the tens of millions of dollars.

Each attack can be divided into several identical stages. At the first stage, a cybercriminal entered the organization’s building under the guise of a courier, job seeker, etc., and connected a device to the local network, for example, in one of the meeting rooms. Where possible, the device was hidden or blended into the surroundings, so as not to arouse suspicion.

The devices used in the DarkVishnya attacks varied in accordance with the cybercriminals’ abilities and personal preferences. In the cases we researched, it was one of three tools:

  • netbook or inexpensive laptop
  • Raspberry Pi computer
  • Bash Bunny, a special tool for carrying out USB attacks

Inside the local network, the device appeared as an unknown computer, an external flash drive, or even a keyboard. Combined with the fact that Bash Bunny is comparable in size to a USB flash drive, this seriously complicated the search for the entry point. Remote access to the planted device was via a built-in or USB-connected GPRS/3G/LTE modem.

Slashdot thread.

Posted on December 7, 2018 at 10:50 AMView Comments

That Bloomberg Supply-Chain-Hack Story

Back in October, Bloomberg reported that China has managed to install backdoors into server equipment that ended up in networks belonging to — among others — Apple and Amazon. Pretty much everybody has denied it (including the US DHS and the UK NCSC). Bloomberg has stood by its story — and is still standing by it.

I don’t think it’s real. Yes, it’s plausible. But first of all, if someone actually surreptitiously put malicious chips onto motherboards en masse, we would have seen a photo of the alleged chip already. And second, there are easier, more effective, and less obvious ways of adding backdoors to networking equipment.

EDITED TO ADD (12/17): SuperMicro now denies it.

Posted on November 30, 2018 at 6:28 AMView Comments

More Spectre/Meltdown-Like Attacks

Back in January, we learned about a class of vulnerabilities against microprocessors that leverages various performance and efficiency shortcuts for attack. I wrote that the first two attacks would be just the start:

It shouldn’t be surprising that microprocessor designers have been building insecure hardware for 20 years. What’s surprising is that it took 20 years to discover it. In their rush to make computers faster, they weren’t thinking about security. They didn’t have the expertise to find these vulnerabilities. And those who did were too busy finding normal software vulnerabilities to examine microprocessors. Security researchers are starting to look more closely at these systems, so expect to hear about more vulnerabilities along these lines.

Spectre and Meltdown are pretty catastrophic vulnerabilities, but they only affect the confidentiality of data. Now that they — and the research into the Intel ME vulnerability — have shown researchers where to look, more is coming — and what they’ll find will be worse than either Spectre or Meltdown. There will be vulnerabilities that will allow attackers to manipulate or delete data across processes, potentially fatal in the computers controlling our cars or implanted medical devices. These will be similarly impossible to fix, and the only strategy will be to throw our devices away and buy new ones.

We saw several variants over the year. And now researchers have discovered seven more.

Researchers say they’ve discovered the seven new CPU attacks while performing “a sound and extensible systematization of transient execution attacks” — a catch-all term the research team used to describe attacks on the various internal mechanisms that a CPU uses to process data, such as the speculative execution process, the CPU’s internal caches, and other internal execution stages.

The research team says they’ve successfully demonstrated all seven attacks with proof-of-concept code. Experiments to confirm six other Meltdown-attacks did not succeed, according to a graph published by researchers.

Microprocessor designers have spent the year rethinking the security of their architectures. My guess is that they have a lot more rethinking to do.

Posted on November 14, 2018 at 3:30 PMView Comments

Security of Solid-State-Drive Encryption

Interesting research: “Self-encrypting deception: weaknesses in the encryption of solid state drives (SSDs)“:

Abstract: We have analyzed the hardware full-disk encryption of several SSDs by reverse engineering their firmware. In theory, the security guarantees offered by hardware encryption are similar to or better than software implementations. In reality, we found that many hardware implementations have critical security weaknesses, for many models allowing for complete recovery of the data without knowledge of any secret. BitLocker, the encryption software built into Microsoft Windows will rely exclusively on hardware full-disk encryption if the SSD advertises supported for it. Thus, for these drives, data protected by BitLocker is also compromised. This challenges the view that hardware encryption is preferable over software encryption. We conclude that one should not rely solely on hardware encryption offered by SSDs.

EDITED TO ADD: The NSA is known to attack firmware of SSDs.

EDITED TO ADD (11/13): CERT advisory. And older research.

Posted on November 6, 2018 at 6:51 AMView Comments

Sidebar photo of Bruce Schneier by Joe MacInnis.