Blogs

For the past few weeks, I have been working on conducting N-day analysis and bug hunting in the io_uring subsystem of the Linux kernel with the guidance of my mentors, Billy and Ramdhan. In this article, I will briefly discuss the io_uring subsystem, as well as my approach to discovering and developing a new kernel exploit technique during my N-day analysis of CVE-2021-41073. I will also discuss two bugs I found while analyzing a new io_uring feature....

Introduction I recently discovered a very interesting kernel vulnerability that allows the reading of arbitrary kernel-mode address. Sadly, the vulnerability was patched in Windows 21H2 (OS Build 22000.675), and I am unsure of the CVE being assigned to it. In this short blog post, I will share my journey of trying to exploit this vulnerability. Although I didn’t finish the exploit in the end, I have decided to share this with everyone anyway....

Introduction Recently, I have had a some work which is related to Sharepoint, so I was learning on how to setup and debug old bugs of Sharepoint. In February, there was a Deserialization bug CVE-2022-22005 (post-auth of course). There is already a detailed analysis blog post about that written by a Vietnamese guy (here). The blog is written with great enthusiasm and detail. I also rely on the details in that blog to setup and debug....

Introduction On 13th September 2021, Google published the security advisory for Google Chrome. That advisory states that Google is aware of two vulnerabilities exploited in the wild, CVE-2021-30632 as RCE and CVE-2021-30633 as Sandbox Escape. In this post, I will talk about the bypass sandbox vulnerability CVE-2021-30633. Man Yue Mo had published a very detailed blog post explaining CVE-2021-30632, which is a Type Confusion bug that leads to RCE in Chrome....

Introduction Looking to practice on source code review, I had been diving into how open-source LMS codebases are structured in order to find undiscovered vulnerabilities. Initially, my main focus had been on Chamilo LMS (their source code can be found on GitHub). Afterwards, I looked into Moodle LMS (their source code can also be found on GitHub). The majority of the findings that were found are the ones you would think of when you hear the words “common web application vulnerabilities”, such as:...

References: STARLabs Advisory STAR-21-1758 In February, Peter found a OOB read vulnerability in libFontParser.dylib. The latest tested version with the vulnerability is macOS Catalina 10.15.4 (19E287). I wrote a guide earlier on setting up a testing environment. Mac Resource Fork Font File References: Font Forge: Macintosh Font Formats Apple: MoreMacintoshToolbx fontTools: macRes It turns out that macOS can load something called a Mac Resource Fork font file....

In the past few months, Akash (@enigmatrix) and I (@daniellimws) worked on developing a taint analysis tool to find bugs in routers, with the guidance of Shi Ji (@puzzor) and Thach (@d4rkn3ss). We had developed a tool based on CVE-2019-8312 to CVE-2019-8319, which are command injection vulnerabilities on the D-Link DIR-878 router with firmware version 1.12A1. The goal was to automate the detection of such bugs. Ideally, the tool should be faster than finding the bugs manually....