Building
by Alexander Moch

Insecure Boot: Injecting initramfs from a debug shell

Many Linux hardening guides focus on well-known protections: full-disk encryption, Secure Boot, and password-protected bootloaders. While these measures are critical, they often overlook a subtle but serious attack vector: the ability to drop into a debug shell via the Initial RAM Filesystem (initramfs). This oversight can enable an attacker with brief physical access to bypass conventional boot protections and inject persistent malware into the system.

In this post, it is demonstrated how this attack works on modern Linux distributions, such as Ubuntu and Fedora, and explained why existing guidance often fails to mention it.

Continue reading “Insecure Boot: Injecting initramfs from a debug shell”

Continue reading
Breaking
by Dennis Heinze

Security Advisory: Airoha-based Bluetooth Headphones and Earbuds

Important note: Some media coverage on this topic falsely or inaccurately depicts the attack conditions. To be clear: Any vulnerable device can be compromised if the attacker is in Bluetooth range. That is the only precondition.

During our research on Bluetooth headphones and earbuds, we identified several vulnerabilities in devices that incorporate Airoha Systems on a Chip (SoCs). In this blog post, we briefly want to describe the vulnerabilities, point out their impact and provide some context to currently running patch delivery processes as described at this year’s TROOPERS Conference.

Continue reading “Security Advisory: Airoha-based Bluetooth Headphones and Earbuds”

Continue reading
Misc
by Tillmann Oßwald

Windows Hello for Business – Past and Present Attacks

Windows Hello for Business is a key component of Microsoft’s passwordless authentication strategy. It enables user authentication not only during system sign-in but also in conjunction with new and advanced features such as Personal Data Encryption, Administrator Protection, and Recall. Rather than depending on traditional passwords, Windows Hello leverages a PIN or biometric methods – such as fingerprint or facial recognition – to unlock cryptographic keys protected by the Trusted Platform Module (TPM).

Continue reading “Windows Hello for Business – Past and Present Attacks”

Continue reading
Breaking
by Nils Emmerich

Disclosure: Multiple Vulnerabilities in X.Org X server prior to 21.1.17 and Xwayland prior to 24.1.7

The X11 Window System has been used since September 1987 for Unix desktop systems, allowing applications to display their windows. Today, one of the server implementations of the protocol is the X.Org X server and XWayland, which both use the same codebase. While reviewing the X server, several legacy security issues were identified. These appear to originate from earlier design stages when security considerations were less prominent. Despite the project’s maturity and widespread use, some of these issues have persisted.

Continue reading “Disclosure: Multiple Vulnerabilities in X.Org X server prior to 21.1.17 and Xwayland prior to 24.1.7”

Continue reading
Misc
by Dennis Heinze

Using the Raspberry Pi Pico W as a Bluetooth Dongle

During our recent research, we experimented with different Bluetooth USB dongles. There are tons of options, and sometimes, it’s challenging to determine what chipset a dongle actually contains, what Bluetooth features it supports, and whether it works on Linux. Inspired by the recent ESP32 Bluetooth research, we wondered whether we could turn our Raspberry Pi Pico Ws into a functioning Bluetooth dongle. We had a few lying around, and the advantage here is that we know exactly which Bluetooth controller it uses – the Infineon CYW43439. It’s also very easy to get one. You can just buy the Pico W for a few bucks, even cheaper than some Bluetooth dongles. You also have a controller family that has been researched quite a bit in the internalblue project. However, there was one disadvantage. We did not find any code that exposes the CYW43439’s HCI interface via USB. So we had to write that on our own.

Continue reading “Using the Raspberry Pi Pico W as a Bluetooth Dongle”

Continue reading
Breaking
by Matthias Ortmann

Disclosure: Input Validation Vulnerabilities in Microsoft Bookings

In a recent customer project, we discovered vulnerabilities in Microsoft Bookings, an online appointment scheduling tool integrated into Microsoft 365, allowing companies to have customers book meetings in available times themselves. The findings originate from insufficient input validation on the public meeting scheduling endpoint. Although Microsoft has largely mitigated this vulnerability, our analysis provides important insights into potential risks and areas for improvement.

Continue reading “Disclosure: Input Validation Vulnerabilities in Microsoft Bookings”

Continue reading
Breaking
by Florian Port

Full Disclosure: Multiple Rundeck Job Command Injections

During a red-teaming-style customer project, we managed to get access to an Rundeck API token. Rundeck is a job scheduler and runbook automation platform designed to automate routine IT tasks across multiple systems. At first, we were excited about this API token because if we could create new Rundeck jobs, we could execute arbitrary code on the Rundeck nodes and move laterally from there. However, it turned out that with this token we only had permissions to run existing jobs.

Continue reading “Full Disclosure: Multiple Rundeck Job Command Injections”

Continue reading
Breaking
by Malte Heinzelmann

Vulnerability Disclosure: Restricted Shell Breakout (CVE-2025-1950) and Privilege Escalation (CVE-2025-1951) in IBM Power Hardware Management Console (HMC)

We discovered a private key for accessing an IBM Hardware Management Console (HMC) during a recent red team engagement. The IBM Hardware Management Console (HMC) is a dedicated management system used to control and manage IBM servers, especially those running on Power Systems (like IBM Power9/Power10) and mainframes (z Systems). After brief research, we identified two security vulnerabilities that can be leveraged to gain root access to the HMC.

Continue reading “Vulnerability Disclosure: Restricted Shell Breakout (CVE-2025-1950) and Privilege Escalation (CVE-2025-1951) in IBM Power Hardware Management Console (HMC)”

Continue reading
Building
by Florian Bausch

Cookie Prefixes – The Lesser Known Cookie Security Feature

When you’re analyzing web applications as a pentester or reading pentest reports about web applications, you will often see findings regarding cookies missing certain security flags. The Set-Cookie HTTP header and the JavaScript document.cookie API allow to use, for example, the flags Secure, Path, and Domain. Common audit and pentest tools will tell you when your web application does not or just insecurely implements these cookie flags.

However, they do not provide optimal security even when using these flags correctly. However, there are mitigations available that partly solve the issues.

Continue reading “Cookie Prefixes – The Lesser Known Cookie Security Feature”

Continue reading
Breaking
by Gregor Debus

CVE-2024-11035: Minor Security Issues in VMware Carbon Black Cloud

We recently conducted a security assessment of VMware Carbon Black Cloud, a unified SaaS solution that integrates endpoint detection and response (EDR), anti-virus, and vulnerability management capabilities. As part of our evaluation, we tested the solution’s ability to detect and prevent malicious activity on Windows and Linux systems. Our analysis focused on the Carbon Black agents for these platforms, and although we did not identify any critical vulnerabilities, we want to share some of the findings in this blog post.

Continue reading “CVE-2024-11035: Minor Security Issues in VMware Carbon Black Cloud”

Continue reading