Note this option is available starting with windows 8. This training is the advanced version of windows kernel exploitation course focused on exploitation of different windows kernel mode vulnerabilities on latest patched version of windows 10 version 1703. Loading the windows kernel driver infosec resources. This patch addressed multiple privately reported vulnerabilities in win32k. Based on these features, this is the novel fuzzing architecture of lldbfuzzer. We will cover basics of windows kernel internals and handson. In our previous research, we used winafl to fuzz userspace applications running on windows, and found over 50 vulnerabilities in adobe reader and microsoft edge for our next challenge, we decided to go after something bigger. Dec 12, 2011 besides the fuzzing functionality, monitoring mode is also available with the tool. By using these tools, you can ensure that drivers ioctl and wmi code validate data buffers and buffer lengths correctly. This talk will present an architecture for fuzzing the windows kernel and. We utilize a hypervisor and intels processor trace pt technology. Important this article contains information that shows you how to help lower security settings or how to turn off security features on a computer. Apr 12, 20 when we build an export driver, we must place it in the c.
Sep 09, 2015 ioctl fuzzer is a tool designed to automate the task of searching vulnerabilities in windows kernel drivers by performing fuzz tests on them. The fuzzers own driver hooks ntdeviceiocontrolfile in order to take control of all ioctl requests throughout the system. Linus torvalds lauds fuzzing for improving linux security. Now that we know how to compile the driver, we also have to look at how to load it into the kernel. Vulnerabilities in windows kernel mode driver could allow remote code execution. The mutation simply consisted in replacing this byte by a random one. And, in his talk called efficient unit test and fuzz tools for kernellibc porting, bamvor will share some ways to improve the trinity fuzzing tool. In our previous research, we used winafl to fuzz userspace applications running on windows, and found over 50 vulnerabilities in adobe reader and microsoft edge. Also, the driver is only loaded into the kernel when were using it from another drivers. This is a project from back in tha dayz, in 20112012. Intro to windows kernel security development ncc group. Fuzzing kernel drivers with interface awareness black hat. Fuzzer for linux kernel drivers tested on ubuntu 14.
We developed a fuzzing framework, that can automatically analyze the kernel sources of a device. At a high level some similarities exist among drivers. The fuzzing process actually follows the following steps. Entering the kernel without a driver and getting interrupt. Even with a recovered interface, it can be very hard to generate. In order to enter the kernel right from an application, one has to set up call gate descriptor in global descriptor table gdt, so that an application can enter the kernel via the call gate. How to temporarily deactivate the kernel mode filter. Fuzzing the windows kernel may 6, 2020 research by. Hardwareassisted feedback fuzzing for os kernels sergej schumilo. Finding kernel race bugs through fuzzing request pdf. Almost every fuzzing expert whom i talked to has started to apply their fuzzing techniques to usb because of the highsecurity impact and potential volume of vulnerabilities due to the complexity of usb itself. This training is focused on exploitation of different windows kernel mode vulnerabilities ranging from pool overflow to use after free.
Using driver verifier manager start driver verifier manager. You can make these changes to work around a specific problem. In june 2016 we opensourced windows driver for intel processor trace. To implement a windows kernel fuzzer fuzzes on the current state logs testcases reproducible and minimisable extensible and modular core kernel, win32k and other drivers is able to run automated at a large scale and most importantly finds a lot of vulns many implementation ideas borrowed from browser fuzzing. Display driver nvidia windows kernel mode driver, version. Jul 17, 2019 syzkaller 1 starts to support usb fuzzing recently and has already found over 80 bugs within the linux kernel 2. Windows 8 and later versions when this option is active, driver verifier applies a set of device driver interface ddi rules that check for the proper interaction between a driver and the kernel interface of the operating system. Many driver fuzzing approaches 5 7 are based on syzkaller. In this paper, we present difuze, an interfaceaware fuzzing tool to automatically generate valid inputs and trigger the execution of the kernel drivers. An advantage of this tool is that it does not rely on captured ioctls.
Then the agent sends 5 the inputs to a target kernel component. This post series is about how we used atscale fuzzing to discover and report a total of 16 vulnerabilities in the handling of truetype and opentype fonts in the windows kernel during the last year. We will understand pool manager internals in order to groom kernel pool memory for reliable exploitation of poolbased vulnerabilities. In this paper, we approach the problem of coverageguided kernel fuzzing in an osindependent and hardwareassisted way. Mar 15, 2012 the fuzzing process actually follows the following steps. Using driver verifier to identify issues with windows. We will cover basics of windows kernel internals and handson fuzzing of windows kernel mode drivers. Level software exploitation both in user and kernel mode, vulnerability research, reverse engineering, hybrid fuzzing, and program analysis.
Windows kernel programming tutorial 1 setting up environment part 1. Windows kernel fuzzing kernelfuzzer 2016 james loureiro and georgi geshev windows system api fuzzer techniques type aware api fuzzing manual definition of generators pertype pregenerated handle tables outputs c code for each testcase to repro after crash. My aim is to both statically audit as well as fuzz the kernel targeting version 3. The ddi compliance checking option is implemented by using a kernelmode library, called verifierext. Each interface will require a different method to provide the fuzzed data. Before you make these changes, we recommend that you evaluate the risks that are associated with implementing this workaround in your particular environment. By doing this, you avoid buffer overruns that can lead to system instability. We emulated a usb mass storage device and dumped the traffic exchanged. Bamvor jian zhang in his experience, the correctness of arguments passing between the c library and core kernel code is a common problem.
Windows graphics driver fuzzing d3dkmtescape entry point for internal graphics functionality each driver implements a proprietary format for pdata a few header fields and command data. Resource windows kernel fuzzers and tools chiheb chebbi. I have heard of people fuzzing plenty of protocols etc. I am aware of the prevailing opinion that fuzzing talks without bugs suck, by definition.
Improving fuzzing tools for more efficient kernel testing. While processing ioctls, the fuzzer will spoof those ioctls conforming to conditions specified in the configuration file. Scanning for valid ioctls codes supported by drivers, generationbased ioctl fuzzing. Select create custom settings for code developers and then click next. You can also use the kernel synchronization delay fuzzing that is included with driver verifier. This means that a driver needs to be able to deal with switching virtual memory contexts between processes, and needs to be written to be incredibly stable because kernel. Iospy and ioattack are tools that perform ioctl and wmi fuzz tests on kernelmode drivers. Syzkaller 1 starts to support usb fuzzing recently and has already found over 80 bugs within the linux kernel 2. Jun 21, 2017 windows kernel programming tutorial 1 setting up environment part 1.
Iospy and ioattack are tools that perform ioctl and wmi fuzz tests on kernel mode drivers. Windows kernel exploitation advanced power of community. In the previous part of the article, weve explained how to compile the windows kernel driver. Interface recovery the interface recovery mechanism is based on llvm analysis passes. Windows kernel fuzzing goals understand the benefits of guided fuzzing. Every step of interface recovery are written as individual passes. Ioctlbf is just a small tool proof of concept that can be used to search vulnerabilities in windows kernel drivers by performing two tasks. Windows kernel fuzzing framework easily scalable reproducible bsod modular and adaptable friendly internal competition windows kernel fuzzing by nils platform agnostic kernel fuzzing by james loureiro and georgi geshev. Google fuzzer finds ton of holes in kernels usb subsystem. We leverage static analysis to compose correctlystructured input in the userspace to explore kernel drivers. Vulnerabilities in windows kernelmode driver could allow remote code execution. Evolutionary kernel fuzzing black hat usa 2017 richard.
Evolutionary kernel fuzzing black hat usa 2017 richard johnson. Oct 16, 2017 linus torvalds release notification for linux 4. Kernel fuzzing model each syscall so we know how to call it and what to pass as arguments this is very hard for ioctls recovering this interface requires lots of manual effort, and as such, ioctls are often neglected when fuzzing. Besides the fuzzing functionality, monitoring mode is also available with the tool. The fuzzer focuses on windows kernel objects and the relationship with different objects. This solution is based on the remote kernel debugger system, so there are two machines.
Like the power framework delay fuzzing option, the kernel synchronization delay fuzzing option uses an algorithm that provides help improve the chances of finding errors in drivers. While processing ioctls, the fuzzer will spoof those ioctls conforming to conditions specified in the. Kinda dirty code, but worked for me to find several bugs in windows drivers. Well be using the service control manager scm, which is a services. Windows kernel fuzzing framework easily scalable reproducible bsod modular and adaptable friendly internal competition windows kernel fuzzing by nils platform agnostic kernel fuzzing by james loureiro and georgi geshev different implementation find different vulnerabilities. Kernel drivers are programs written against windows nts native api rather than the win32 subsystems api and which execute in kernel mode on the underlying hardware. The monitoring mode allows logging of irps, optionally including their hex dumps, into a file andor a console. F2fs support for grub2 pending implemented features. For every driver the tool identifies all the ioctl entry points, aswellasthecorrespondingstructures,anddevicefilenames. Jun 27, 2016 this post series is about how we used atscale fuzzing to discover and report a total of 16 vulnerabilities in the handling of truetype and opentype fonts in the windows kernel during the last year. However, once usermode code is not allowed to access gdt, above mentioned authors used a kernelmode driver in order to set up call gate descriptor. At first sight, it seemed to be exactly what we were looking for.
Syzfuzzer is the main executable for driving the fuzzing process inside the guest vm. Then, we decided to fuzz the configuration descriptor, and particularly the bnumendpoints field. A wellknown kernel fuzzing tool is syzkaller 3, which has found hundreds of real bugs in linux device drivers 4. Mar 16, 2014 inmemory kernel driver ioctl fuzzing using python im sharing one of my kernel driver ioctl fuzzer which operates completely from user land. Display driver nvidia windows kernel mode driver, version 186. Furthermore, if a process fuzzes its own kernel, a kernel crash highly impacts the performance of the fuzzer as the os needs to reboot. Announcing the fifth release candidate for the linux kernel version 4. Select select individual settings from a full list. With a kernel driver, each interface type can be interesting to test. Ioctl fuzzer is a tool designed to automate the task of searching vulnerabilities in windows kernel drivers by performing fuzz tests on them. Syzkaller has its own syntax to describe programs, syscalls. Windows driver security and fuzzing resources mwri fuzzing the.
Kernel synchronization delay fuzzing windows drivers. He has authored hacksys extreme vulnerable driver hevd which has. Linus torvalds says targeted fuzzing is improving linux. The fuzzer s own driver hooks ntdeviceiocontrolfile in order to take control of all ioctl requests throughout the system. Inmemory kernel driverioctlfuzzing using python im sharing one of my kernel driver ioctl fuzzer which operates completely from user land. When the option is selected, driver verifier inserts random delays at various points in the threads. My first question is simple is fuzzing the linux kernel possible. One of the unique challenges of driver fuzzing is that each driver is different. To run this script you should know at least one process which sends ioctl to your target device you are fuzzing.
937 1390 851 794 224 1035 1290 1020 693 989 941 955 551 607 1471 662 1499 515 160 752 1073 1377 983 1010 1035 1450 419 1229 998 177 919 1116 139 24 509 1164 1323 1213 1183 58 538 1007 96 532 1008 1499