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{ Category Archives } csrss

Windows System Call and CSR API tables updated

Having the first spare weekend in a really long time, I have decided it was high time to update some (all) of the tables related to Windows system calls and CSR API I once created and now try to maintain. This includes NT API syscalls for the 32-bit and 64-bit Intel platforms, win32k.sys syscalls for […]

Defeating Windows Driver Signature Enforcement #3: The Ultimate Encounter

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 […]

Defeating Windows Driver Signature Enforcement #2: CSRSS and thread desktops

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 […]

0-day Windows XP SP3 Denial of Service (CSRSS Crash #1)

A rather short blog post today, as I am currently on my vacations. After publishing two, quite extensive write-ups regarding vulnerabilities in the Windows “CSRSS” component at Microsoft July Patch Tuesday: CVE-2011-1281: A story of a Windows CSRSS Privilege Escalation vulnerability CVE-2011-1282: User-Mode NULL Pointer Dereference & co. I would like to shortly discuss the […]

CVE-2011-1282: User-Mode NULL Pointer Dereference & co.

After a short break, today I would like to present the details of another Windows CSRSS vulnerability, fixed during the recent Microsoft Patch Tuesday cycle (advisory MS11-056) – CVE-2011-1282, also called CSRSS Local EOP SrvSetConsoleLocalEUDC Vulnerability. Although not as spectacular as the previous one (see: CVE-2011-1281: A story of a Windows CSRSS Privilege Escalation vulnerability), […]

CVE-2011-1281: A story of a Windows CSRSS Privilege Escalation vulnerability

Today, I would like to present a detailed description of the CVE-2011-1281 vulnerability [1], which was reported by me several months ago and patched today, together with four other bugs marked as the Elevation of Privileges class, on the occasion of the monthly Microsoft Patch Tuesday cycle (see Microsoft Security Bulletin MS11-056, a summary of […]

HITB E-Zine Issue 005 finally made public

Hello, Today, I would like to present the fifth issue of the well-known Hack In The Box e-magazine, originally brought back to life by Zarul Shahrin, in January last year (see the complete release history here). As usual, every Windows Internals maniac can find something for himself: this time, I described some of the most […]

HITB eZine Issue 004 is public!

Hey! Traditionally – during the annual, last Hack in the Box 2010 conference edition held in Kuala-Lumpur, Malaysia (follow HITBSecConf @ Twitter), an IT-security related magazine is released ;) Since three issues, I have been contributing to the paper with my Windows-oriented articles. This time, I would like to present a publication called Creating custom […]

Windows CSRSS Write Up: Inter-process Communication (part 2/3)

A quick beginning note: My friend d0c_s4vage has created a technical blog and posted his first text just a few days ago. The post entry covers a recent, critical libpng vulnerability discovered by this guy; the interesting thing is that, among others, the latest Firefox and Chrome versions were vulnerable. Feel free to take a […]

Windows CSRSS Write Up: Inter-process Communication (part 1/3)

In the second post of the Windows CSRSS Write Up series, I would like to explain how the practical communication between the Windows Subsystem and user’s process takes place under the hood. Due to the fact that some major improvements have been introduced in Windows Vista and later, the entire article is split into two […]