(Collaborative post by Mateusz “j00ru” Jurczyk and Gynvael Coldwind) A few days ago we (Gynvael and I) gave a talk during the SyScan’13 conference in the fine city of Singapore, and as promised (though with a slight delay), today we are publishing both the slide deck and a white paper discussing memory access pattern analysis [...]
In the most recent blog post (“Fun facts: Windows kernel and guard pages”), we have learned how the code coverage of kernel routines referencing user-mode memory can be determined by taking advantage of the fact that kernel-mode code triggers guard page exceptions in the same way as user-mode does. Today, I will present how the [...]
It has been a while since I last posted here, so I guess it’s high time to get back to work and share some more interesting Windows kernel internals goodies. Before we get to that, however, let’s start with a few announcements. First of all, there is a number of great infosec conferences coming up [...]
(Collaborative post by Mateusz “j00ru” Jurczyk and Gynvael Coldwind) Almost five months ago, Gynvael Coldwind and I wrote about an effort to improve the security of popular PDF parsing and rendering software; back then, we were primarily focused on the Chrome PDF Renderer and latest Adobe Reader applications. In order to achieve our results, we [...]
Microsoft addressed several Windows kernel vulnerabilities in the MS12-075 security bulletin released in November this year, some of them residing in every version of the win32k.sys driver shipped with the NT family line systems. Apart from the obviously extremely interesting remote web browser => ring-0 arbitrary code execution issue, there have also been two other [...]
I hope you haven’t got bored with bypassing the Driver Signature Enforcement mechanism (present on all 64-bit Microsoft Windows operating systems since Vista) just yet – in either case, stay calm… this is going to be the last post of the series. After using multiple drivers shipped with the OS in the default configuration to [...]
First of all, it has been reported to me that the system call list for Microsoft Windows Vista SP0 available at http://j00ru.vexillium.org/ntapi was wrong, containing syscall numbers for beta2 version of the system instead of the actual RTM Service Pack 0. The issue has already been resolved – apologies for any confusion this might have [...]
To stand by my claim that the Microsoft Windows operating system has been built on the fundamental assumption that administrative privileges would always be equivalent to granting the ability to run arbitrary ring-0 code, I have decided to briefly discuss yet another portion of some Windows internals and how they could be easily misused by [...]
One of the obvious things about the Windows operating system for anyone actively working on its kernel security is that the Driver Signature Enforcement (DSE in short) is not effective and can be bypassed with relative ease by any determined individual. From a historical perspective, the “feature” was introduced in the 64-bit build of Windows [...]
(Bug found by Gynvael Coldwind, exploit developed by Mateusz “j00ru” Jurczyk) Several months back we have been playing with different file systems on various system platforms, examining the security posture and robustness of numerous device drivers’ implementations. One of the configurations we spent some time on was the commonly used NTFS on Microsoft Windows – [...]