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.
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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.
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Continue readingFull 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.
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Continue readingVulnerability 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 readingCVE-2024-11035: Minor Security Issues in VMware Carbon Black Cloud
Continue reading “CVE-2024-11035: Minor Security Issues in VMware Carbon Black Cloud”
Continue readingCVE-2025-20908: Use of insufficiently random values in Samsung’s Auracast implementation
As part of our research into the Auracast feature set in Bluetooth, we also started looking into vendor implementations. At the time we started with our research, there weren’t a lot of products on the market yet. But new products are coming out pretty frequently now.
One of the vendors that had Auracast implemented pretty early was Samsung. At the time the Samsung Galaxy S23 and S24 phones were able to broadcast Audio, while the Galaxy Buds were able to join these broadcasts.
In our previous blog post we analyze the security of Auracast broadcasts. In short, broadcasts can be encrypted by specifying a so-called Broadcast Code (or Passcode). We show that the key derivation used to derive an AES key from the Broadcast Code is not sufficient to properly protect the broadcast. The weak key derivation, combined with the way the encryption works, allows an attacker to perform an efficient offline brute-force attack against captured Auracast packets. However, when the Broadcast Code is chosen properly, this attack can be made very difficult and likely economically unreasonable.
However, we found that the Bluetooth specification is lacking in this regard. Both the specification of the Broadcast Code itself, and the example values given in the specification and other documents are inadequate.
This, in our opinion, inadequate specification and the poorly chosen examples of Broadcast Codes lead us to suspect that vendors may not be aware of the requirements for a secure Broadcast Code.
This is essentially what happened with Samsung’s implementation.
Continue readingPart I: Bluetooth Auracast from a Security Researcher’s Perspective
Auracast, the new Bluetooth LE Broadcast Audio feature has gained some publicity in the past months. The Bluetooth SIG has introduced the LE Audio feature-set to the Bluetooth 5.2 Specification in 2019 and vendors are only now starting to implement it. Auracast facilitates broadcasting audio over Bluetooth LE to a potentially unlimited number of devices. It does not require pairing or interaction between the sender and the receivers.
We also presented this topic at 38c3. This blog post will contain similar contents albeit with some more details.
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Continue readingVulnerability Disclosure: Command Injection in Kemp LoadMaster Load Balancer (CVE-2024-7591)
While conducting security research, I identified a critical vulnerability in Kemp’s LoadMaster Load Balancer. This vulnerability is a Command Injection and allows full system compromise. It requires no authentication and can be exploited remotely by having access to the Web User Interface (WUI). Kemp found that all LoadMaster versions up to and including version 7.2.60.0 and also the multi-tenant hypervisors up to and including version 7.1.35.11 are affected.
Kemp LoadMaster is a widely used Load Balancing Application that can commonly be seen in customer engagements. Therefore, we decided to take a closer look as part of our regular research projects.
As promised in the Announcement: Progress / Kemp LoadMaster CVE-2024-7591, I will go into detail about how I identified the vulnerability, where the vulnerable part of the code is, how the vulnerability can be exploited, and finally, how the vendor fixed this vulnerability.
Continue readingVulnerability Disclosure: Authentication Bypass in Vaultwarden versions < 1.32.5 - CVE-2024-55225
During a penetration test for a customer, we briefly assessed Vaultwarden, an open-source online password safe. In June 2024, the German Federal Office for Information Security (BSI) published results1 of a static and dynamic test of the Vaultwarden server component. Therefore, only a partial source code audit was performed during our assessment. However, a quick look was needed to find some glaring issues with the authentication.
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Disclosure: Potential Limitations of Apple ADE in Corporate Usage Scenarios
Apple Automated Device Enrollment (ADE) is presented as a way to automate and simplify the enrollment process of Apple devices within Mobile Device Management (MDE) solutions. This blog post is aimed at organizations currently planning or even already using this feature and making you, the reader, aware of potential limitations of this process that might otherwise not be clearly addressed in your companies’ device management process.
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