Breaking, Misc

Change Your BLE Passkey Like You Change Your Underwear

Using a static passkey for Bluetooth Low Energy pairing is insecure. Recent versions of the Bluetooth specification contain an explicit warning about this. However, in practice, we often see static passkeys being used. Moreover, there are no public implementations of proofs-of-concept that can practically show why using a static passkey is an issue. This is why we implemented one.

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Breaking, Misc

fpicker: Fuzzing with Frida

Introduction

In this post, I will introduce fpicker. Fpicker is a Frida-based coverage-guided, mostly in-process, blackbox fuzzing suite. Its most significant feature is the AFL++ proxy mode which enables blackbox in-process fuzzing with AFL++ on platforms supported by Frida. In practice, this means that fpicker enables fuzzing binary-only targets with AFL++ on potentially any system that is supported by Frida. For example, it allows fuzzing a user-space application on the iOS operating system, such as the Bluetooth daemon bluetoothd – which was part of the original motivation to implement fpicker.
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Building

Reversing C++ Without Getting a Heart Attack – DEvirtualize VIrtual Calls With Devi

TLDR: This blogpost presents devi, a tool that can help you devirtualize virtual calls in C++ binaries. It uses Frida to trace the execution of a binary and uncover the call sources and destinations of virtual calls. The collected information can then be viewed in IDA Pro, Binary Ninja, or Ghidra. The plugin adds the respective control-flow edges allowing further analysis (using different plugins) or simply providing more comfort when analyzing C++ binaries.

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Building, Misc

How can data from fitness trackers be obtained and analyzed with a forensic approach?

The use of Internet of Things devices is continuously increasing: People buy devices, such as smart assistants, to make their lives more comfortable or fitness trackers to assess sports activities. According to the Pew Research Center [1], every fifth American wears a device to track their fitness. In Germany, the number increases likewise. The increasing number of fitness trackers in use can also be seen in criminal proceedings, as there exist more and more cases where these devices provide evidence.

Which useful evidential information fitness trackers collect and how to analyze them forensically was part of a paper that we presented at WACCO 2020 this year [2]. The goal was to develop an open source program to support investigators analyzing data that fitness trackers provide and to give a general approach on how to analyze fitness trackers.

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Events

The Dog Whisperer’s Handbook

Generally speaking, I’m more of a Cat type of guy, but I have to say I really love BloodHound. And if you do too, you are in for a treat…
Last week, the ERNW Insight Active Directory Security Summit took place in Heidelberg. (More Info)
For this occasion, @Enno_Insinuator asked me if I would like to deliver a BloodHound Workshop, and of course I accepted the challenge…

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Building

PoSh_ATTCK – ATT&CK Knowledge at your PowerShell Fingertips…

When I recently joined the Windows Security team at ERNW, Enno asked me if I wanted to write a ‘welcome’ blogpost on a topic of my choosing… Up for the challenge, and since I had been playing with BloodHound & Cypher for the last couple of months, I first thought I would do something on that topic.

However, after gathering my thoughts and some Cypher I had collected here and there, I realized that the topic of Bloodhound Cypher might actually require several blog posts… And so I changed my mind. I will keep the joys of Cypher for later, and in this post, I will talk about a tiny tool I wrote to query the Mitre ATT&CK™ knowledge base from the comfort of a PowerShell prompt. Continue reading “PoSh_ATTCK – ATT&CK Knowledge at your PowerShell Fingertips…”

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Breaking

Erlang distribution RCE and a cookie bruteforcer

In one of the last pentests we’ve found an epmd (Erlang port mapper daemon) listening on a target system (tcp/4369). It is used to coordinate distributed erlang instances, but also can lead to a RCE, given one knows the so called “authentication cookie”. Usually, this cookie is located in ~/.erlang.cookie and is generated by erlang at the first start. If not modified or set manually it is a random string [A:Z] with a length of 20 characters. If an attacker gains this cookie, a RCE is quite easy – as I like to describe below.

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Misc

(Mostly) New, Interesting, and Security-focused Open Source Projects

Troopers ’17 – the 10th edition – madness is over and hopefully all of you are well rested and recovered after this special week. Of course the rest of the world did not stand still and thus Google lifted the curtains on a new public portal collecting and promoting the Open Source Software projects developed by employees of Google: opensource.google.com. There are a lot of interesting projects that might incubate new interesting developments. And even security oriented tools and projects (51 at the time of writing to be precise) are publically available Continue reading “(Mostly) New, Interesting, and Security-focused Open Source Projects”

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Breaking

KNXmap: A KNXnet/IP Scanning and Auditing Tool

Users of the KNX, a standard for home automation bus systems, may already have come across KNXnet/IP (also known as EIBnet/IP): It is an extension for KNX that defines Ethernet as a communication medium for KNX which allows communication with KNX buses over IP driven networks. Additionally, it enables one to couple multiple bus installations over IP gateways, or so called KNXnet/IP gateways.

In the course of some KNX related research we’ve had access to various KNXnet/IP gateways from different vendors, most of them coupled in a lab setup for testing purposes. The typical tools used for such tasks are ETS, the professional software developed by the creators of KNX (proprietary, test licenses available) and eibd, an open source implementation of the KNX standard developed by the TU Vienna.

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