This Week In Security: GitHub Actions, SHA-1 Retirement, And A Self-Worming Vulnerability

December 23, 2022 by Jonathan Bennett 6 Comments

It should be no surprise that running untrusted code in a GitHub Actions workflow can have unintended consequences. It’s a killer feature, to automatically run through a code test suite whenever a pull request is opened. But that pull request is run in some part of the target’s development environment, and there’s been a few clever attacks found over the years that take advantage of that. There’s now another one, what Legit Security calls Github Environment Injection, and there were some big-name organizations vulnerable to it.

The crux of the issue is the $GITHUB_ENV file, which contains environment variables to be set in the Actions environment. Individual variables get added to this file as part of the automated action, and that process needs to include some sanitization of data. Otherwise, an attacker can send an environment variable that includes a newline and completely unintended environment variable. And an unintended, arbitrary environment variable is game over for the security of the workflow. The example uses the NODE_OPTIONS variable to dump the entire environment to an accessible output. Any API keys or other secrets are revealed.

This particular attack was reported to GitHub, but there isn’t a practical way to fix it architecturally. So it’s up to individual projects to be very careful about writing untrusted data into the $GITHUB_ENV file.

Continue reading “This Week In Security: GitHub Actions, SHA-1 Retirement, And A Self-Worming Vulnerability” →

Students Rebel Against Heat-Sensing Crotch Monitor Surveillance Devices

December 12, 2022 by Lewin Day 180 Comments

Surveillance has become a ubiquitous part of modern life. Public spaces are dotted with CCTV cameras inside and out. Recent years have seen the technology spread to the suburbs with porch cameras spreading the eye of big tech and law enforcement ever further.

Outside of mere cameras, companies are rushing to develop all manner of new devices to surveil individuals, too. One such device intended to track students quickly drew the ire of scholars at Northeastern University, and the cohort fought back.

Continue reading “Students Rebel Against Heat-Sensing Crotch Monitor Surveillance Devices” →

This Week In Security: Rackspace Falls Over, Poison Ping, And The WordPress Race

December 9, 2022 by Jonathan Bennett 17 Comments

In what’s being described as a Humpty-Dumpty incident, Rackspace customers have lost access to their hosted Exchange service, and by extension, lots of archived emails. The first official word of trouble came on December 2nd, and it quickly became clear that this was more than the typical intern-tripped-over-the-cable incident. Nearly a week later, Rackspace confirmed what observers were beginning to suspect, it was a ransomware attack. There’s not a lot of other answers yet, and the incident FAQ answers are all variations on a theme.

Our investigation into the incident is ongoing and will take time to complete. To ensure the integrity of the ongoing investigation, we do not have additional details to share at this time.

Knowing the security issues that have plagued Microsoft Exchange over the last couple of months, one has to wonder if Rackspace was breached as a result of the PowerShell problems. What’s staggering is that a week after the incident, Rackspace still has no timeline for service restoration.

Rackspace isn’t the only major ransomware attack this week, as a hospital in Versailles has partially shut down due to another ransomware attack. Operations were canceled, and work has to be done the old fashioned way, without the network to support.

Continue reading “This Week In Security: Rackspace Falls Over, Poison Ping, And The WordPress Race” →

side by side, showing hardware experiments with capacitor gating through FETs, an initial revision of the modchip board with some fixes, and a newer, final, clean revision.

A Modchip To Root Starlink User Terminals Through Voltage Glitching

November 28, 2022 by Arya Voronova 37 Comments

A modchip is a small PCB that mounts directly on a larger board, tapping into points on that board to make it do something it wasn’t meant to do. We’ve typically seen modchips used with gaming consoles of yore, bypassing DRM protections in a way that a software hacks couldn’t quite do. As software complexity and therefore attack surface increased on newer consoles, software hacks have taken the stage. However, on more integrated pieces of hardware, we’ll still want to return to the old methods – and that’s what this modchip-based hack of a Starlink terminal brings us.

[Lennert Wouters]’ team has been poking and prodding at the Starlink User Terminal, trying to get root access, and needed to bypass the ARM Trusted Firmware boot-time integrity checks. The terminal’s PCB is satellite-dish-sized, so things like laser fault injection are hard to set up – hence, they went the voltage injection route. Much poking and prodding later, they developed a way to reliably glitch the CPU into verifying a faulty firmware, and got to a root shell – the journey described in a BlackHat talk embedded below. Continue reading “A Modchip To Root Starlink User Terminals Through Voltage Glitching” →

A slide from the presentation, showing the power trace of the chip, while it's being pulsed with the laser at various stages of execution

Defeating A Cryptoprocessor With Laser Beams

November 26, 2022 by Arya Voronova 21 Comments

Cryptographic coprocessors are nice, for the most part. These are small chips you connect over I2C or One-Wire, with a whole bunch of cryptographic features implemented. They can hash data, securely store an encryption key and do internal encryption/decryption with it, sign data or validate signatures, and generate decent random numbers – all things that you might not want to do in firmware on your MCU, with the range of attacks you’d have to defend it against. Theoretically, this is great, but that moves the attack to the cryptographic coprocessor.

In this BlackHat presentation (slides), [Olivier Heriveaux] talks about how his team was tasked with investigating the security of the Coldcard cryptocurrency wallet. This wallet stores your private keys inside of an ATECC608A chip, in a secure area only unlocked once you enter your PIN. The team had already encountered the ATECC608A’s predecessor, the ATECC508A, in a different scenario, and that one gave up its secrets eventually. This time, could they break into the vault and leave with a bag full of Bitcoins?

Lacking a vault door to drill, they used a powerful laser, delidding the IC and pulsing different areas of it with the beam. How do you know when exactly to pulse? For that, they took power consumption traces of the chip, which, given enough tries and some signal averaging, let them make educated guesses on how the chip’s firmware went through the unlock command processing stages. We won’t spoil the video for you, but if you’re interested in power analysis and laser glitching, it’s well worth 30 minutes of your time.

You might think it’s good that we have these chips to work with – however, they’re not that hobbyist-friendly, as proper documentation is scarce for security-through-obscurity reasons. Another downside is that, inevitably, we’ll encounter them being used to thwart repair and reverse-engineering. However, if you wanted to explore what a cryptographic coprocessor brings you, you can get an ESP32 module with the ATECC608A inside, we’ve seen this chip put into an IoT-enabled wearable ECG project, and even a Nokia-shell LoRa mesh phone!

Continue reading “Defeating A Cryptoprocessor With Laser Beams” →

Sick Beats: Using Music And Smartphone To Attack A Biosafety Room

November 23, 2022 by Dan Maloney 15 Comments

Imagine a movie featuring a scene set in a top-secret bioweapons research lab. The villain, clad in a bunny suit, strides into the inner sanctum of the facility — one of the biosafety rooms where only the most infectious and deadliest microorganisms are handled. Tension mounts as he pulls out his phone; surely he’ll use it to affect some dramatic hack, or perhaps set off an explosive device. Instead, he calls up his playlist and… plays a song? What kind of villain is this?

As it turns out, perhaps one who has read a new paper on the potential for hacking biosafety rooms using music. The work was done by University of California Irvine researchers [Anomadarshi Barua], [Yonatan Gizachew Achamyeleh], and [Mohammad Abdullah Al Faruque], and focuses on the negative pressure rooms found in all sorts of facilities, but are of particular concern where they are used to prevent pathogens from escaping into the world at large. Continue reading “Sick Beats: Using Music And Smartphone To Attack A Biosafety Room” →

Scramblepad Teardown Reveals Complicated, Expensive Innards

November 18, 2022 by Donald Papp 28 Comments

What’s a Scramblepad? It’s a type of number pad in which the numbers aren’t in fixed locations, and can only be seen from a narrow viewing angle. Every time the pad is activated, the buttons have different numbers. That way, a constant numerical code isn’t telegraphed by either button wear, or finger positions when punching it in. [Glen Akins] got his hands on one last year and figured out how to interface to it, and shared loads of nice photos and details about just how complicated this device was on the inside.

Just one of the many layers inside the Scramblepad.

Patented in 1982 and used for access control, a Scramblepad aimed to avoid the risk of someone inferring a code by watching a user punch it in, while also preventing information leakage via wear and tear on the keys themselves. They were designed to solve some specific issues, but as [Glen] points out, there are many good reasons they aren’t used today. Not only is their accessibility poor (they only worked at a certain height and viewing angle, and aren’t accessible to sight-impaired folks) but on top of that they are complex, expensive, and not vandal-proof.

[Glen]’s Scramblepad might be obsolete, but with its black build, sharp lines, and red LED 7-segment displays it has an undeniable style. It also includes an RFID reader, allowing it to act as a kind of two-factor access control.

On the inside, the reader is a hefty piece of hardware with multiple layers of PCBs and antennas. Despite all the electronics crammed into the Scramblepad, all by itself it doesn’t do much. A central controller is what actually controls door access, and the pad communicates to this board via an unencrypted, proprietary protocol. [Glen] went through the work of decoding this, and designed a simplified board that he plans to use for his own door access controller.

In the meantime, it’s a great peek inside a neat piece of hardware. You can see [Glen]’s Scramblepad in action in the short video embedded below.

Continue reading “Scramblepad Teardown Reveals Complicated, Expensive Innards” →