How A Pentester Gets Root

Have you ever wanted to be a fly on the wall, watching a penetration tester attack a new machine — working their way through the layers of security, ultimately leveraging what they learned into a login?  What tools are used, what do they reveal, and how is the information applied? Well good news, because [Phani] has documented a step-by-step of every action taken to eventually obtain root access on a machine — amusingly named DevOops — which was set up specifically for testing.

[Phani] explains every command used (even the dead-end ones that reveal nothing useful in this particular case) and discusses the results in a way that is clear and concise. He starts from a basic port scan, eventually ending up with root privileges. On display is an overall process of obtaining general information.  From there, [Phani] methodically moves towards more and more specific elements. It’s a fantastic demonstration of privilege escalation in action, and an easy read as well.

For some, this will give a bit of added insight into what goes on behind the scenes in some of the stuff covered by our regular feature, This Week in Security.

This Week In Security: Chrome 0-day,Cassandra, And A Cisco PoC

Running Chrome or a Chromium-based browser? Check for version 98.0.4758.102, and update if you’re not running that release or better. Quick tip, use chrome://restart to trigger an immediate restart of Chrome, just like the one that comes after an update. This is super useful especially after installing an update on Linux, using apt, dnf, or the like.

CVE-2022-0609 is the big vulnerability just patched, and Google has acknowledged that it’s being exploited in the wild. It’s a use-after-free bug, meaning that the application marks a section of memory as returned to the OS, but then accesses that now-invalid memory address. The time gap between freeing and erroneously re-using the memory allows malicious code to claim that memory as its own, and write something unexpected.

Google has learned their lesson about making too many details public too early, and this CVE and associated bug aren’t easily found in in the Chromium project’s source, and there doesn’t seem to be an exploit published in the Chromium code testing suite. Continue reading “This Week In Security: Chrome 0-day,Cassandra, And A Cisco PoC”

This Week In Security: Samba, Wormhole Crypto Heist, And A Bogus CVE

Samba has a very serious vulnerability, CVE-2021-44142, that was just patched in new releases 4.13.17, 4.14.12, and 4.15.5. Discovered by researchers at TrendMicro, this unauthenticated RCE bug weighs in at a CVSS 9.9. The saving grace is that it requires the fruit VFS module to be enabled, which is used to support MacOS client and server interop. If enabled, the default settings are vulnerable. Attacks haven’t been seen in the wild yet, but go ahead and get updated, as PoC code will likely drop soon.

Crypto Down the Wormhole

One notable selling point to cryptocurrencies and Web3 are smart contracts, little computer programs running directly on the blockchain that can move funds around very quickly, without intervention. It’s quickly becoming apparent that the glaring disadvantage is these are computer programs that can move money around very quickly, without intervention. This week there was another example of smart contracts at work, when an attacker stole $326 million worth of Ethereum via the Wormhole bridge. A cryptocurrency bridge is a service that exists as linked smart contracts on two different blockchains. These contracts let you put a currency in on one side, and take it out on the other, effectively transferring currency to a different blockchain. Helping us make sense of what went wrong is [Kelvin Fichter], also known appropriately as [smartcontracts].

When the bridge makes a transfer, tokens are deposited in the smart contract on one blockchain, and a transfer message is produced. This message is like a digital checking account check, which you take to the other side of the bridge to cash. The other end of the bridge verifies the signature on the “check”, and if everything matches, your funds show up. The problem is that one one side of the bridge, the verification routine could be replaced by a dummy routine, by the end user, and the code didn’t catch it.

It’s a hot check scam. The attacker created a spoofed transfer message, provided a bogus verification routine, and the bridge accepted it as genuine. The majority of the money was transferred back across the bridge, where other user’s valid tokens were being held, and the attacker walked away with 90,000 of those ETH tokens. Continue reading “This Week In Security: Samba, Wormhole Crypto Heist, And A Bogus CVE”

Remoticon 2021 // Colin O’Flynn Zaps Chips (And They Talk)

One of the many fascinating fields that’s covered by Hackaday’s remit lies in the world of hardware security, working with physical electronic hardware to reveal inner secrets concealed in its firmware. Colin O’Flynn is the originator of the ChipWhisperer open-source analysis and fault injection board, and he is a master of the art of glitching chips. We were lucky enough to be able to welcome him to speak at last year’s Remoticon on-line conference, and now you can watch the video of his talk below the break. If you need to learn how to break RSA encryption with something like a disposable camera flash, this is the talk for you.

This talk is an introduction to signal sniffing and fault injection techniques. It’s well-presented and not presented as some unattainable wizardry, and as his power analysis demo shows a clearly different trace on the correct first letter of a password attack the viewer is left with an understanding of what’s going on rather than hoping for inspiration in a stream of the incomprehensible. The learning potential of being in full control of both instrument and target is evident, and continues as the talk moves onto fault injection with an introduction to power supply glitching as a technique to influence code execution.

Schematic of an EM injector built from a camera flash.
Schematic of an EM injector built from a camera flash.

Continue reading “Remoticon 2021 // Colin O’Flynn Zaps Chips (And They Talk)”

BBQ lighter fault injector

Blast Chips With This BBQ Lighter Fault Injection Tool

Looking to get into fault injection for your reverse engineering projects, but don’t have the cash to lay out for the necessary hardware? Fear not, for the tools to glitch a chip may be as close as the nearest barbecue grill.

If you don’t know what chip glitching is, perhaps a primer is in order. Glitching, more formally known as electromagnetic fault injection (EMFI), or simply fault injection, is a technique that uses a pulse of electromagnetic energy to induce a fault in a running microcontroller or microprocessor. If the pulse occurs at just the right time, it may force the processor to skip an instruction, leaving the system in a potentially exploitable state.

EMFI tools are commercially available — we even recently featured a kit to build your own — but [rqu]’s homebrew version is decidedly simpler and cheaper than just about anything else. It consists of a piezoelectric gas grill igniter, a little bit of enameled magnet wire, and half of a small toroidal ferrite core. The core fragment gets a few turns of wire, which then gets soldered to the terminals on the igniter. Pressing the button generates a high-voltage pulse, which gets turned into an electromagnetic pulse by the coil. There’s a video of the tool in use in the Twitter thread, showing it easily glitching a PIC running a simple loop program.

To be sure, a tool as simple as this won’t do the trick in every situation, but it’s a cheap way to start exploring the potential of fault injection.

Thanks to [Jonas] for the tip.

Long Range Burglar Alarm Relies On LoRa Modules

[Elite Worm] had a problem; there had been two minor burglaries from a storage unit. The unit had thick concrete walls, cellular signal was poor down there, and permanent wiring wasn’t possible. He thus set about working on a burglar alarm that would fit his unique requirements.

An ESP32 is the heart of the operation, paired with a long-range LoRa radio module running at 868 MHz. This lower frequency has much better penetration when it comes to thick walls compared to higher-frequency technologies like 4G, 5G or WiFi. With a little coil antenna sticking out the top of the 3D-printed enclosure, the device was readily able to communicate back to [Elite Worm] when the storage unit was accessed illegitimately.

With an eye to security, the device doesn’t just warn of door open events. If signal is lost from the remote transmitter in the storage unit, perhaps due to an advanced adversary cutting the power, the alarm will also be raised. There’s still some work to be done on the transmitter side, though, as [Elite Worm] needs to make sure the door sensor is reliable under all conditions.

Many put their hardware skills to work in service of security, and we regularly see proprietary alarm systems modified by enterprising hackers. Video after the break.

Continue reading “Long Range Burglar Alarm Relies On LoRa Modules”

This Week In Security: Geopolitical Hacktivism, Antivirus Mining, And Linux Malware

The CIA Hacktivists have launched a sort of ransomware campaign against the Belarusian rail system, but instead of cryptocurrency, they want the release of political prisoners and removal of Russian soldiers. This could be called an example of cyber-terrorism, though there is a reasonable theory that this is a state-sponsored hack, masquerading as hacktivism. What does seem certain is that something has interrupted rail transit, and a group on Twitter has produced convincing proof of a breach.

Your Antivirus Now Includes a CryptoMiner

Don’t look now, but your latest update of Norton 360 or Avira may have installed a cryptocurrency mining module. The silver lining is that some sanity has been retained, and you have to opt-in to the crypto scheme before your machine starts spending its spare cycles on mining. For users who do, they’re put into a mining pool, making for small payouts for most hardware. Norton, naturally, takes a 15% fee off the top for their trouble.

The State of Linux Malware

There used to be an adage that Linux machines don’t get malware. That’s never really been quite true, but the continued conquest of the server landscape has had the side effect of making Linux malware an even greater danger. Crowdstrike has seen a 35% increase in Linux malware in 2021, with three distinct categories leading the charge: XorDDoS, Mozi, and Mirai. Continue reading “This Week In Security: Geopolitical Hacktivism, Antivirus Mining, And Linux Malware”