richinseattle

Building a grsec-patched Linux kernel for Debian 8 and DigitalOcean

It's possible to run a custom (instead of hypervisor-managed) kernel for use with Debian 8.x on a DigitalOcean droplet.

We'll build one with grsecurity, "an extensive security enhancement to the Linux kernel that defends against a wide range of security threats through intelligent access control, memory corruption-based exploit prevention, and a host of other system hardening".

Note: The stable patches for Linux 3.14.x and 3.2.x are not publicly available anymore, so we'll be applying the free 4.2.x (test) patch. The URLs and filenames in this document may become outdated, so fetch the latest from grsecurity.net and kernel.org.

Install dependencies:

richinseattle

# Installing
qemu-system-x86_64 -bios /usr/share/ovmf/ovmf_x64.bin -enable-kvm -cpu host -smp 4 -m 2048 -cdrom ~/Downloads/Win10_English_x64.iso -net nic,model=virtio -net user -drive file=~/vm/win10.hd.img.raw,format=raw,if=virtio -vga qxl -drive file=~/Downloads/virtio-win-0.1.105.iso,index=1,media=cdrom

# Running
qemu-system-x86_64 -bios /usr/share/ovmf/ovmf_x64.bin -enable-kvm -cpu host -smp 4 -m 4096 -net nic,model=virtio -net user -drive file=~/vm/win10.hd.img.raw,format=raw,if=virtio -vga qxl -usbdevice tablet -rtc base=utc

richinseattle

/* SMBLoris attack proof-of-concept
 * 
 * Copyright 2017 Hector Martin "marcan" <marcan@marcan.st>
 *
 * Licensed under the terms of the 2-clause BSD license.
 *
 * This is a proof of concept of a publicly disclosed vulnerability.
 * Please do not go around randomly DoSing people with it.
 *
 * Tips: do not use your local IP as source, or if you do, use iptables to block

richinseattle

/* Anonymous
 *
 * How to use: sudo rm -rf /
 *
 * greetz: djrbliss, kad, Ac1dB1tch3z, nVidia!
 *
 * Only complete fix patch nvidia drivers and redefine
 * IS_BLACKLISTED_REG_OFFSET:

#define IS_BLACKLISTED_REG_OFFSET(nv, offset, length) 1

richinseattle

Each of these commands will run an ad hoc http static server in your current (or specified) directory, available at http://localhost:8000. Use this power wisely.

Discussion on reddit.

Python 2.x

$ python -m SimpleHTTPServer 8000

richinseattle

#!/usr/bin/env python

import os
import sys
import os.path
import site

try:
    import binaryninja
    print "Binary Ninja API Installed"

richinseattle

"Algorithm","Hash","CatalogPath","Hint"
"SHA256","71A0AEC9941BA21780C3BED570AEAF3BC5B9473BB6662F7CAF194F33C0E1B918","C:\Windows\InfusedApps\Frameworks\Microsoft.Advertising.Xaml_10.1705.4.0_x64__8wekyb3d8bbwe\AppxMetadata\CodeIntegrity.cat",
"SHA256","F5EEEC38876E48617643A9E735A30B9EC3D08D77075CD81F239A15626E3F7DD5","C:\Windows\InfusedApps\Frameworks\Microsoft.Advertising.Xaml_10.1705.4.0_x64__8wekyb3d8bbwe\AppxMetadata\CodeIntegrity.cat",
"SHA256","4BA33EC224E42FC929BA6487041C2C4275C5BCA66CD89471A09BC7F522A5661F","C:\Windows\InfusedApps\Frameworks\Microsoft.Advertising.Xaml_10.1705.4.0_x86__8wekyb3d8bbwe\AppxMetadata\CodeIntegrity.cat",
"SHA256","71A0AEC9941BA21780C3BED570AEAF3BC5B9473BB6662F7CAF194F33C0E1B918","C:\Windows\InfusedApps\Frameworks\Microsoft.Advertising.Xaml_10.1705.4.0_x86__8wekyb3d8bbwe\AppxMetadata\CodeIntegrity.cat",

richinseattle

/*
 * linux 2.6.37-3.x.x x86_64, ~100 LOC
 * gcc-4.6 -O2 semtex.c && ./a.out
 * 2010 [email protected], salut!
 *
 * update may 2013:
 * seems like centos 2.6.32 backported the perf bug, lol.
 * jewgold to 115T6jzGrVMgQ2Nt1Wnua7Ch1EuL9WXT2g if you insist.
 */

richinseattle

//
// CVE-2006-0741 reloaded
// CVE-2014-4699 actually
// [email protected]
//

#define _GNU_SOURCE
#include <sched.h>
#include <stdlib.h>
#include <sys/ptrace.h>

richinseattle

// Gets a pointer to the PEB for x86, x64, ARM, ARM64, IA64, Alpha AXP, MIPS, and PowerPC.

// This relies on MS-compiler intrinsics.
// It has only been tested on x86/x64/ARMv7.

inline PEB* NtCurrentPeb() {
#ifdef _M_X64
	return (PEB*)(__readgsqword(0x60));
#elif _M_IX86
	return (PEB*)(__readfsdword(0x30));