Assignment #3: Egghunter This time the assignment was very interesting, here the requirements: study an egg hunting shellcode and create a working demo, it should be configurable for different payloads. As many before me, I’ve started my research journey with Skape’s papers: “Searching Process Virtual Address Space”. I was honestly amazed by the paper content, […]
This post will be a bit different from the usual technical stuff, mostly because I was not able to find any reliable solution on Internet and I would like to help other people having the same doubt/question, it’s nothing advanced, it’s just something useful that I didn’t see posted before. During a recent engagement I […]
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Assignment #4: Custom Shellcode Encoder As the 4th SLAE’s assignment I was required to build a custom shellcode encoder for the execve payload, which I did, here how. Encoder Implementations I’ve decided to not relay on XORing functionalities as most antivirus solutions are now well aware of this encoding schema, the same reason for which […]
Assignment #5: Metasploit Shellcode Analysis Fifth SLAE’s assignment requires to dissect and analyse three different Linux x86 Metasploit Payload. Metasploit currently has 35 different payloads but almost half of it are Meterpreter version, thus meaning staged payloads. I’ve then decided to skip meterpreter payloads as they involve multiple stages and higher complexity that will break […]
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Assignment #6: Polymorphic Shellcode Sixth SLAE’s assignment requires to create three different (polymorphic) shellcodes version starting from published Shell Storm’s examples. I’ve decided to take this three in exam: http://shell-storm.org/shellcode/files/shellcode-752.php – linux/x86 execve (“/bin/sh”) – 21 bytes http://shell-storm.org/shellcode/files/shellcode-624.php – linux/x86 setuid(0) + chmod(“/etc/shadow”,0666) – 37 bytes http://shell-storm.org/shellcode/files/shellcode-231.php – linux/x86 open cd-rom loop (follows “/dev/cdrom” symlink) […]
Assignment #7: Custom Shellcode Crypter Seventh and last SLAE’s assignment requires to create a custom shellcode crypter. Since I had to implement an entire encryption schema both in python as an helper and in assembly as the main decryption routine, I’ve opted for something simple. I’ve chosen the Tiny Encryption Algorithm (TEA) as it does […]
During this period of social isolation, a friend of mine proposed to play some online “board games”. He proposed “Tabletopia”: a cool sandbox virtual table with more than 800 board games. Tabletopia is both accessible from its own website and from the Steam’s platform. While my friends decided to play from their browser, I’ve opted […]
TL;DR: Shenzhen Sricctv Technology Sricam CMS (SricamPC.exe) <= v.184.108.40.206(4) and DeviceViewer (DeviceViewer.exe) <= v.220.127.116.11 (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 […]
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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). Contents PrintDemon primer, how the exploit works? PrinterPort WritePrinter Shadow Job File Binary Diffing CVE-2020-1048 […]
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Following a recent engagement, I had the opportunity to check and verify some possible vulnerabilities on an ASP .NET application. Despite not being the deepest technical nor innovative blog post you could find on the net, I have decided to post it anyway in order to explain the methodology I adopt to verify possible vulnerabilities. […]
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TL; DR: this blog post serves as an advisory for both: CVE-2020-28054: An Authorization Bypass vulnerability affecting JamoDat – TSMManager Collector v. <= 18.104.22.168 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 […]
We are proud to announce that ECG got its first major update. ECG: is the first and single commercial solution (Static Source Code Scanner) able to analyze & detect real and complex security vulnerabilities in TCL/ADP source-code. ECG’s v2.0 New Features On-Premises Deploy: Scan your code repository on your secure and highly-scalable offline appliance with a local […]
This blog post is part of a series and a re-posting of the original article “Fuzzing 101” that I have written for Yarix on YLabs. Introduction In this article, I would like to introduce fuzz testing as part of a vast overview of software testing approaches used to discover bugs and vulnerabilities within applications, protocols, […]
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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 […]
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 Page This blog post is a re-post of the […]
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At the beginning of the month, Sentinel One disclosed five high severity vulnerabilities in Dell’s firmware update driver. As the described vulnerability appeared not too complicated to exploit, a lot of fellow security researchers started weaponizing it. I was one of, if not the first tweeting about weaponizing it into a _SEP_TOKEN_PRIVILEGES overwrite exploit, and […]
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Last week SentinelOne disclosed a “high severity” flaw in HP, Samsung, and Xerox printer’s drivers (CVE-2021-3438); the blog post highlighted a vulnerable strncpy operation with a user-controllable size parameter but it did not explain the reverse engineering nor the exploitation phase of the issue. With this blog post, I would like to analyse the vulnerability […]
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It’s no secret that, since the beginning of the year, I’ve spent a good amount of time learning how to fuzz different Windows software, triaging crashes, filling CVE forms, writing harnesses and custom tools to aid in the process. Today I would like to sneak peek into my high-level process of designing a Homemade Fuzzing […]
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 […]
This blog post serves as an advisory for a couple of MSI’s products that are affected by multiple high-severity vulnerabilities in the driver components they are shipped with. All the vulnerabilities are triggered by sending specific IOCTL requests and will allow to: Directly interact with physical memory via the MmMapIoSpace function call, mapping physical memory […]
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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 […]
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 […]
In case you’re wondering why I’m not posting as regularly as before, with the new year, I’ve finally transitioned into a fully offensive vulnerability research and exploit development role at Exodus Intelligence that fulfilled my career dream (BTW, we’re currently hiring). In the last couple of months, I’ve worked on some exciting and challenging bugs. […]
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