Security Hacks

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This Week In Security: Plenty Of Patches, Replacing Old Gear, And Phrack Calls For Papers

March 13, 2026 by 7 Comments

When Friday the Thirteenth and Patch Tuesday happen on the same week, we’re surely in for a good time.

Anyone who maintains any sort of Microsoft ecosystem knows by now to brace for impact come Patch Tuesday; March brings the usual batch of “interesting” issues, including:

  • Two high-risk Microsoft Office vulnerabilities (CVE-2026-26110 and CVE-2026-26113), both of which allow execution of arbitrary code with no user interaction other than opening a hostile file. Vulnerabilities like these are especially dangerous in environments where transferring Office documents is considered normal, such as (unsurprisingly) offices, but also for home users who may not be savvy enough to avoid opening hostile files. Arbitrary code execution allows the attacker to run essentially any commands the user would be able to run themselves, typically leveraging it to install remote access or keyboard logging malware.
  • Excel gets a different vulnerability, CVE-2026-26144, which allows leaking of data through a cross-site scripting vulnerability. Coupled with CoPilot Agent, this can be used to leak contents of spreadsheets, again with no direct user interaction.

On the server and container side, this month includes a fairly typical collection of patches for SQL Server, and vulnerabilities in the Microsoft-hosted device pricing and payment orchestrator services, which have been automatically patched by Microsoft. Continue reading “This Week In Security: Plenty Of Patches, Replacing Old Gear, And Phrack Calls For Papers” →

Secure Communication, Buried In A News App

March 9, 2026 by 28 Comments

Cryptography is a funny thing. Supposedly, if you do the right kind of maths to a message, you can send it off to somebody else, and as long as they’re the only one that knows a secret little thing, nobody else will be able to read it. We have all sorts of apps for this, too, that are specifically built for privately messaging other people.

Only… sometimes just having such an app is enough to get you in trouble. Even just the garbled message itself could be proof against you, even if your adversary can’t read it. Enter The Guardian. The UK-based media outlet has deployed a rather creative and secure way of accepting private tips and information, one which seeks to provide heavy cover for those writing in with the hottest scoops.

Continue reading “Secure Communication, Buried In A News App” →

This Week In Security: Getting Back Up To Speed

March 6, 2026 by 11 Comments

Editor’s Note: Over the course of nearly 300 posts, Jonathan Bennett set a very high bar for this column, so we knew it needed to be placed in the hands of somebody who could do it justice. That’s why we’re pleased to announce that Mike Kershaw AKA [Dragorn] will be taking over This Week In Security! Mike is a security researcher with decades of experience, a frequent contributor to 2600, and perhaps best known as the creator of the Kismet wireless scanner.

He’ll be bringing the column to you regularly going forward, but given the extended period since we last checked in with the world of (in)security, we thought it would be appropriate to kick things off with a review of some of the stories you may have missed.

Hacking like it’s 2009, or 1996

Hello all!  It’s a pleasure to be here, and it already seems like a theme of the new year so far has bringing in the old bugs – what’s old is new again, and 2026 has seen several fixes to some increasingly ancient bugs.

Telnet

Reported on the OpenWall list, the GNU inetd suite brings an update to the telnet server (yes, telnet) that closes a login bug present since 2015 linked to environment variable sanitization.

Under the covers, the telnet daemon uses /bin/login to perform user authentication, but also has the ability to pass environment variables from the client to the host. One of these variables, USER, is passed directly to login — unfortunately this time with no checking to see what it contains. By simply passing a USER variable of “-froot”, login would accept the “-f” argument, or “treat this user as already logged in”. Instant root!

If this sounds vaguely familiar, it might be because the exact same bug was found in the Solaris telnetd service in 2007, including using the “-f” argument in the USER variable. An extremely similar bug targeting other variables (LD_PRELOAD) was found in the FreeBSD telnetd service in 2009, and other historical similar bugs have afflicted AIX and other Unix systems in the past.

Of course, nobody in 2026 should be running a telnet service, especially not exposed to the Internet, but it’s always interesting to see the old style of bugs resurface.

Glibc

Also reported on the OpenWall list, glibc — the GNU LibC library which underpins most binaries on Linux systems, providing kernel interfaces, file and network I/O, string manipulation, and most other common functions programmers expect — has killed another historical bug, present since 1996 in the DNS resolver functions which could be used to expose some locations in the stack.

Although not exploitable directly, the getnetbyaddr resolution functions could still ease in breaking ASLR, making other exploits viable.

Address Space Layout Randomization (ASLR) is a common method of randomizing where in memory a process and its data are loaded, making trivial exploits like buffer overflows much harder to execute. Being able to expose the location of the binary in memory by leaking stack locations weakens this mechanism, possibly exposing a vulnerable program to more traditional attacks.

MSHTML

In February, Microsoft released fixes under CVE-2026-21513 for the MSHTML Trident renderer – the one used in Internet Explorer 5. Apparently still present in Windows, and somehow still accessible through specific shortcut links, it’s the IE5 and Active-X gift that keeps giving, being actively exploited.

Continue reading “This Week In Security: Getting Back Up To Speed” →

Exploring Security Vulnerabilities In A Cheap WiFi Extender

March 3, 2026 by 15 Comments

If all you want is just a basic WiFi extender that gets some level of network connectivity to remote parts of your domicile, then it might be tempting to get some of those $5, 300 Mbit extenders off Temu as [Low Level] recently did for a security audit. Naturally, as he shows in the subsequent analysis of its firmware, you really don’t want to stick this thing into your LAN. In this context it is also worrying that the product page claims that over a 100,000 of these have been sold.

Starting the security audit is using $(reboot) as the WiFi password, just to see whether the firmware directly uses this value in a shell without sanitizing. Shockingly, this soft-bricks the device with an infinite reboot loop until a factory reset is performed by long-pressing the reset button. Amusingly, after this the welcome page changed to the ‘Breed web recovery console’ interface, in Chinese.

Here we also see that it uses a Qualcomm Atheros QCA953X SoC, which incidentally is OpenWRT compatible. On this new page you can perform a ‘firmware backup’, making it easy to dump and reverse-engineer the firmware in Ghidra. Based on this code it was easy to determine that full remote access to these devices was available due to a complete lack of sanitization, proving once again that a lack of input sanitization is still the #1 security risk.

In the video it’s explained that it was tried to find and contact a manufacturer about these security issues, but this proved to be basically impossible. This leaves probably thousands of these vulnerable devices scattered around on networks, but on the bright side they could be nice targets for OpenWRT and custom firmware development.

Continue reading “Exploring Security Vulnerabilities In A Cheap WiFi Extender” →

Removing The BIOS Administrator Password On A ThinkPad Takes Timing

February 15, 2026 by 14 Comments
This would be a bad time to slip. (Credit: onionboots, YouTube)
This would be a bad time to slip. (Credit: onionboots, YouTube)

In the olden days, an administrator password on a BIOS was a mere annoyance, one quickly remedied by powering off the system and pulling its CMOS battery or moving a jumper around. These days, you’re more likely to find a separate EEPROM on the mainboard that preserves the password. This, too, is mostly just another annoyance, as [onionboots] knew. All it takes is shorting out this EEPROM at the right time to knock it offline, with the ‘right time’ turning out to be rather crucial.

While refurbishing this laptop for a customer, he thought it’d be easy: the guide he found said he just had to disassemble the laptop to gain access to this chip, then short out its reset pin at the right time to make it drop offline and keep it shorted. Important here is that you do not short it when you are still booting the system, or it won’t boot. This makes for some interesting prodding of tiny pins with a metal tool.

Continue reading “Removing The BIOS Administrator Password On A ThinkPad Takes Timing” →

When Clever Hardware Hacks Bite Back: A Password Keeper Device Autopsy

February 7, 2026 by 10 Comments

Sometimes you have this project idea in your mind that seems so simple and straightforward, and which feels just so right that you have to roll with it. Then, years later you stumble across the sad remnants of the tearful saga and the dismal failure that it portrays. Do you put it away again, like an unpleasant memory, or write it up in an article, as a tearful confession of past sins? After some coaxing by a friend, [Alessandro] worked up the courage to detail how he set about making a hardware-only password keeper, and why it failed.

The idea was so simple: the device would pretend to be a keyboard and type the passwords for you. This is not that unusual, as hardware devices like the Mooltipass do something similar. Even better, it’d be constructed only out of parts lying around, including an ATtiny85 and an HD44780 display, with bit-banged USB connectivity.

Prototyping the hardware on a breadboard.

Overcoming the challenge of driving the LC display with one pin on the MCU required adding a 74HC595 demultiplexer and careful timing, which sort of worked when the stars aligned just right. Good enough, but what about adding new passwords?

This is where things quickly skidded off the tracks in the most slapstick way possible, as [Alessandro] solved the problem of USB keyboard HID devices being technically ‘output-only’, by abusing the indicator statuses for Caps Lock, Num Lock, and Scroll Lock. By driving these from the host PC in just the right way you can use them as a sort of serial protocol. This incidentally turned out to be the most reliable part of the project.

Where the project finally tripped and fell down the proverbial flight of stairs was when it came to making the bit-banged USB work reliably. As it turns out, USB is very unforgiving with its timing unlike PS/2, making for an infuriating user experience. After tossing the prototype hardware into a box, this is where the project gathered dust for the past years.

If you want to give it a try yourself, maybe using an MCU that has more GPIO and perhaps even a USB hardware peripheral like the STM32F103, ESP32-S3 or something fruit-flavored, you can take a gander at the project files in the GitHub repository.

We’re always happy to see projects that (ab)use the Lock status indicators, it’s always been one of our favorite keyboard hacks.

A pair of printed circuit boards are shown against a pink background. The right circuit board is plugged into a USB cable, and has several LED indicators on. The left board is plugged into the other at 45-degree angle, and has no visible components.

Tamper Detection With Time-Domain Reflectometry

January 24, 2026 by 13 Comments

For certain high-security devices, such as card readers, ATMs, and hardware security modules, normal physical security isn’t enough – they need to wipe out their sensitive data if someone starts drilling through the case. Such devices, therefore, often integrate circuit meshes into their cases and regularly monitor them for changes that could indicate damage. To improve the sensitivity and accuracy of such countermeasures, [Jan Sebastian Götte] and [Björn Scheuermann] recently designed a time-domain reflectometer to monitor meshes (pre-print paper).

Many meshes are made from flexible circuit boards with winding traces built into the case, so cutting or drilling into the case breaks a trace. The problem is that most common ways to detect broken traces, such as by resistance or capacitance measurements, aren’t easy to implement with both high sensitivity and low error rates. Instead, this system uses time-domain reflectometry: it sends a sharp pulse into the mesh, then times the returning echoes to create a mesh fingerprint. When the circuit is damaged, it creates an additional echo, which is detected by classifier software. If enough subsequent measurements find a significant fingerprint change, it triggers a data wipe.

The most novel aspect of this design is its affordability. An STM32G4-series microcontroller manages the timing, pulse generation, and measurement, thanks to its two fast ADCs and a high-resolution timer with sub-200 picosecond resolution. For a pulse-shaping amplifier, [Jan] and [Björn] used the high-speed amplifiers in an HDMI redriver chip, which would normally compensate for cable and connector losses. Despite its inexpensive design, the circuit was sensitive enough to detect when oscilloscope probes contacted the trace, pick up temperature changes, and even discern the tiny variations between different copies of the same mesh.

It’s not absolutely impossible for an attacker to bypass this system, nor was it intended to be, but overcoming it would take a great deal of skill and some custom equipment, such as a non-conductive drill bit. If you’re interested in seeing such a system in the real world, check out this teardown of a payment terminal. One of the same authors also previously wrote a KiCad plugin to generate anti-tamper meshes.

Thanks to [mark999] for the tip!