Windows Drivers Reverse Engineering Methodology

With this blog post I’d like to sum up my year-long Windows Drivers research; share and detail my own methodology for reverse engineering (WDM) Windows drivers, finding some possible vulnerable code paths as well as understanding their exploitability. I've tried to make it as "noob-friendly" as possible, documenting all the steps I usually perform during my research and including a bonus exercise for the readers. Setting up the lab While in the past, setting up a lab for kernel debugging was a...

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Driver Buddy Reloaded

As part of my continuous security research journey, during this year I’ve spent a good amount of time reverse-engineering Windows drivers and exploiting kernel-mode related vulnerabilities. While in the past there were (as far as I know), at least two good IDA plugins aiding in the reverse engineering process: DriverBuddy of NCC Group. win_driver_plugin of F-Secure. unfortunately, nowadays, they are both rusty, out of date and broken on the latest version of IDA. They relied on external dependencies, were lacking documentation and...

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Crucial’s MOD Utility LPE – CVE-2021-41285

Crucial Ballistix MOD Utility is a software product that can be used to customize and control gaming systems, specifically LED colours and patterns, memory, temperature, and overclock. During my vulnerability research, I’ve discovered that this software utilizes a driver, MODAPI.sys, containing multiple vulnerabilities and allowing an attacker to achieve local privilege escalation from a low privileged user to NT AUTHORITY\SYSTEM. This blog post is a re-post of the original article “Crucial’s MOD Utility LPE” that I have written for Yarix on YLabs. Advisory...

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Exploiting System Mechanic Driver

Last month we (last & VoidSec) took the amazing Windows Kernel Exploitation Advanced course from Ashfaq Ansari (@HackSysTeam) at NULLCON. The course was very interesting and covered core kernel space concepts as well as advanced mitigation bypasses and exploitation. There was also a nice CTF and its last exercise was: “Write an exploit for System Mechanics”; no further hints were given. We took the challenge as that was a good time to test our newly acquired knowledge and understanding of the...

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Fuzzing: FastStone Image Viewer & CVE-2021-26236

This blog post is a re-post of the original article “Fuzzing: FastStone Image Viewer & CVE-2021-26236” that I have written for Yarix on YLabs. Introduction In my precedent blog post I’ve introduced “fuzzing” from a theoretical point of view. As I’ve previously anticipated, today I’m going to disclose the fuzzing methodology, process and samples that led me to discover five different vulnerabilities in FastStone Image Viewer v.<=7.5. I’ll also go over the root cause analysis of CVE-2021-26236 and how to achieve Arbitrary...

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CVE-2020-1337 – PrintDemon is dead, long live PrintDemon!

Banner Image by Sergio Kalisiak TL; DR: I will explain, in details, how to trigger PrintDemon exploit and dissect how I’ve discovered a new 0-day; Microsoft Windows EoP CVE-2020-1337, a bypass of PrintDemon’s recent patch via a Junction Directory (TOCTOU). After Yarden Shafir’s & Alex Ionescu’s posts (PrintDemon, FaxHell) and their call to action, I’ve started diving into the PrintDemon exploit. PrintDemon is the catching name for Microsoft CVE-2020-1048: Windows Print Spooler Elevation of Privilege Vulnerability which is affecting (according to Microsoft),...

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Windows Kernel Debugging & Exploitation Part1 – Setting up the lab

Recently I was thrilled with the opportunity to build a PoC for ms-14-066 vulnerability aka “winshock” (CVE-2014-6321). While that will be material for another blog post, in order to debug the vulnerability, I had to set up a lab with windows kernel mode debugging enabled. So, without any further ado, here my setup and the steps used in order to enable Windows Kernel Debug. Setup Host system: Windows 10 with VMware Workstation 15.1.0 (build-13591040) Guest systems: Windows 7 x86 ultimate sp1 (debugger) Windows...

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Uncommon Phishing and Social Engineering Techniques

Sorry if you didn’t hear anything from me for a while but it was a very busy year and the new incoming one will bring a lot of news for me and for the voidsec project, I will speak about it soon in a new blog post. Today I will like to write about some uncommon techniques that I’ve used during social engineering and phishing campaign. Maybe they are not overpowered but they can be pretty useful. Behind the Scene All of these...

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Reportage: Deftcon 2014

Nella giornata di ieri, a Milano, si è tenuta la terza conferenza nazionale del sistema operativo DEFT, un evento nato per far incontrare sviluppatori e utilizzatori della distribuzione e per presentare le novità nel mondo dell’analisi forense. DEFT, strumento standard nell’ambito dell’informatica forense (computer forensics) utilizzato da Carabinieri, Polizia di Stato, Nasa, Fineco e British Telecom, è una distribuzione Linux Live basata su Ubuntu nella quale vengono raccolti gli strumenti open-source utili al data recovery e all’analisi forense. Qui trovate la presentazione...

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Windows XP

Forse non tutti sanno che, oggi, (8 aprile 2014) a distanza di dodici anni dalla sua nascita, il Sistema Operativo Windows XP viene ufficialmente "abbandonato" e come annunciato da Microsoft non verranno più effettuati aggiornamenti di sicurezza, ne verrà più fornito il supporto tecnico. Le conseguenze potrebbero essere gravi per specifici settori e per tutti gli stati in cui il sistema operativo è ancora predominante. Cerchiamo di evidenziare le criticità di quest'avvenimento: Le ripercussioni sotto il punto di vista della sicurezza sono gravi,...

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