2,918 research outputs found
InternalBlue - Bluetooth Binary Patching and Experimentation Framework
Bluetooth is one of the most established technologies for short range digital
wireless data transmission. With the advent of wearables and the Internet of
Things (IoT), Bluetooth has again gained importance, which makes security
research and protocol optimizations imperative. Surprisingly, there is a lack
of openly available tools and experimental platforms to scrutinize Bluetooth.
In particular, system aspects and close to hardware protocol layers are mostly
uncovered.
We reverse engineer multiple Broadcom Bluetooth chipsets that are widespread
in off-the-shelf devices. Thus, we offer deep insights into the internal
architecture of a popular commercial family of Bluetooth controllers used in
smartphones, wearables, and IoT platforms. Reverse engineered functions can
then be altered with our InternalBlue Python framework---outperforming
evaluation kits, which are limited to documented and vendor-defined functions.
The modified Bluetooth stack remains fully functional and high-performance.
Hence, it provides a portable low-cost research platform.
InternalBlue is a versatile framework and we demonstrate its abilities by
implementing tests and demos for known Bluetooth vulnerabilities. Moreover, we
discover a novel critical security issue affecting a large selection of
Broadcom chipsets that allows executing code within the attacked Bluetooth
firmware. We further show how to use our framework to fix bugs in chipsets out
of vendor support and how to add new security features to Bluetooth firmware
Weighted -estimates for elliptic equations with measurable coefficients in nonsmooth domains
We obtain a global weighted estimate for the gradient of the weak
solutions to divergence form elliptic equations with measurable coefficients in
a nonsmooth bounded domain. The coefficients are assumed to be merely
measurable in one variable and to have small BMO semi-norms in the remaining
variables, while the boundary of the domain is supposed to be Reifenberg flat,
which goes beyond the category of domains with Lipschitz continuous boundaries.
As consequence of the main result, we derive global gradient estimate for the
weak solution in the framework of the Morrey spaces which implies global
Hoelder continuity of the solution.Comment: 27 page
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