voidsec2022-03-10T14:42:04+01:00With 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...
voidsec2022-01-14T08:55:49+01:00As 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unfortunately, nowadays, they are both rusty, out of date and broken on the latest version of IDA.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...
CVE-2020-1337 – PrintDemon is dead, long live PrintDemon!
voidsec2022-01-14T09:05:26+01:00Banner 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),...