Chaining Bugs: NVIDIA GeForce Experience (GFE) Command Execution
NVIDIA GeForce Experience (GFE) v.<= 3.21 is affected by an Arbitrary File Write vulnerability in the GameStream/ShadowPlay plugins, where log files are created using NT AUTHORITY\SYSTEM level permissions, which lead to Command Execution and Elevation of Privileges (EoP). NVIDIA Security Bulletin – April 2021 NVIDIA Acknowledgements PageIntroduction
Some time ago I was looking for...
Malware Analysis: Ragnarok Ransomware
The analysed sample is a malware employed by the Threat Actor known as Ragnarok. The ransomware is responsible for files’ encryption and it is typically executed, by the actors themselves, on the compromised machines. The name of the analysed executable is xs_high.exe, but others have been found used by the same ransomware family (such as...
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...
Fuzzing: FastStone Image Viewer & CVE-2021-26236
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...