Introduction to Trusted Execution Environment: ARM's TrustZone

Increasing popularity of connected devices in recent years has led devices manufacturers to deal with security issues in a more serious way than before. In order to address these issues appropriately, a specification has emerged to define a way to ensure the integrity and confidentiality of data running in the entity implementing this specification.

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Android Bluetooth Vulnerabilities in the March 2018 Security Bulletin

The March 2018 Android Security Bulletin includes fixes for 10 vulnerabilities in its Bluetooth stack, some of which were also independently discovered by Quarkslab, but were fixed while we were in the process of reporting them to Google (spoiler alert: we have reported a few more new Bluetooth vulnerabilities to the Android team — we'll disclose the details after they get fixed). This blogpost shows technical details for a couple of these fixed bugs, which can be triggered remotely and without any user interaction, as well as proof-of-concept code for them.

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Reverse Engineering the Win32k Type Isolation Mitigation

Given the popularity of GDI Bitmap objects for exploitation of kernel vulnerabilities -due to the fact that almost any kind of memory corruption vulnerability (except for NULL-writes) could be used to reliably gain arbitrary R/W primitives over the kernel memory by abusing Bitmaps- Microsoft decided to kill exploitation techniques based on Bitmaps. In order to do this, Windows 10 Fall Creators Update (also known as Windows 10 1709) introduced the Type Isolation feature, an exploitation mitigation in the Win32k subsystem, which splits the memory layout of SURFACE objects, the internal representation of Bitmaps on the kernel side. This blogpost takes a deep dive into the details of how Type Isolation is implemented.

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