A security engineer focusing on fuzzers, exploits, and mitigations for Linux and Android kernels.
A 3-day Linux kernel exploitation frenzy!
This training guides researchers through the field of Linux kernel exploitation. In a series of practical labs, the training explores the process of exploiting kernel bugs in a modern Linux distribution on the x86-64 architecture.
The training starts with the beginner topics but proceeds into advanced areas as well. The beginner chapters include learning the techniques to escalate privileges and bypass foundational mitigations in x86-64 kernels. The advanced chapters are dedicated to slab (heap) exploitation, including an in-depth analysis of the kernel allocators’ internals.
This is the story of how I figured out a way to turn my ThinkPad X1 Carbon 6th Gen laptop into a programmable USB device by enabling the xDCI controller.
As a result, the laptop can now be used to emulate arbitrary USB devices such as keyboards or storage drives. Or to fuzz USB hosts with the help of Raw Gadget and syzkaller. Or to even run Facedancer with the help of the Raw Gadget–based backend. And do all this without any external hardware.
The journey of enabling xDCI included fiddling with Linux kernel drivers, xHCI, DWC3, ACPI, BIOS/UEFI, Boot Guard, TPM, NVRAM, PCH, PMC, PSF, IOSF, and P2SB, and making a custom USB cable 😱
How would an attacker remotely take over a personal Linux or Android device? Send a malicious link and get code execution through the browser? Or target a messenger or an email client? Well, how about sending a series of network packets and owning the kernel directly 😋
This article covers my experience with fuzzing the Linux kernel externally over the network. I’ll explain how I extended a kernel fuzzer called syzkaller for this purpose and show off the found bugs. The article also includes an introduction to syzkaller and its advanced feature — pseudo-syscalls.
Sadly, to find that one bug to take over the Internet — I failed. But I did manage to find a one-shot RCE in a non-public kernel flavor.
A Telegram channel about Linux kernel security. Me and Alexander Popov regularly post links to materials about exploits, fuzzers, mitigations, and other security-related things there.