Windows Exploitation Challenge – Blue Frost Security 2022

Last month, during Ekoparty, Blue Frost Security published a Windows challenge. Since having a Windows exploitation challenge, is one of a kind in CTFs, and since I've found the challenge interesting and very clever, I've decided to post about my reverse engineering and exploitation methodology. Challenge Requests Only Python solutions without external libraries will be accepted The goal is to execute the Windows Calculator (calc.exe) The solution should work on Windows 10 or Windows 11 Process continuation is desirable (not mandatory) You...

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...

Tivoli Madness

TL; DR: this blog post serves as an advisory for both: CVE-2020-28054: An Authorization Bypass vulnerability affecting JamoDat – TSMManager Collector v. <= 6.5.0.21 A Stack Based Buffer Overflow affecting IBM Tivoli Storage Manager - ITSM Administrator Client Command Line Administrative Interface (dsmadmc.exe) Version 5, Release 2, Level 0.1. Unfortunately, after I had one of the rudest encounters with an Hackerone’s triager, these are the takeaways: IBM Tivoli Storage Manager has reached its end of life support and will not be...

A tale of a kiosk escape: ‘Sricam CMS’ Stack Buffer Overflow

TL;DR: Shenzhen Sricctv Technology Sricam CMS (SricamPC.exe) <= v.1.0.0.53(4) and DeviceViewer (DeviceViewer.exe) <= v.3.10.12.0 (CVE-2019-11563) are affected by a local Stack Buffer Overflow. By creating a specially crafted "Username" and copying its value in the "User/mail" login field, an attacker will be able to gain arbitrary code execution in the context of the currently logged-in user. Please Note: by default, Sricam CMS requires elevation and runs in High Integrity mode; exploitation of the above software will result in a compromise of...