Choi ChoiSG

KrbRelay with RBCD Privilege Escalation HOWTO

Short HOWTO about one use case of the work from Cube0x0 (KrbRelay) and others.

TL;DR

No-Fix Local Privilege Escalation from low-priviliged domain user to local system on domain-joined computers.

Prerequisites:

LDAP signing not required on Domain Controller (default!)

Circumventing Deep Packet Inspection with Socat and rot13

I have a Linux virtual machine inside a customer's private network. For security, this VM is reachable only via VPN + Citrix + Windows + a Windows SSH client (eg PuTTY). I am tasked to ensure this Citrix design is secure, and users can not access their Linux VM's or other resources on the internal private network in any way outside of using Citrix.

The VM can access the internet. This task should be easy. The VM's internet gateway allows it to connect anywhere on the internet to TCP ports 80, 443, and 8090 only. Connecting to an internet bastion box on one of these ports works and I can send and receive clear text data using netcat. I plan to use good old SSH, listening on tcp/8090 on the bastion, with a reverse port forward configured to expose sshd on the VM to the public, to show their Citrix gateway can be circumvented.

Rejected by Deep Packet Inspection

I hit an immediate snag. The moment I try to establish an SSH or SSL connection over o

Minimal APIs at a glance

This document now exists on the official ASP.NET core docs page.

Application
- WebApplication
- WebApplicationBuilder
Request Handling
- Routing
- Parameter Binding

I've transformed this gist into a git repository.

Whenever you research a certain vulnerability ask yourself these questions and please answer them for us

Logging

Does the exploited service write a log?
(check ls -lrt /var/log or lsof +D /var/log/ or lsof | grep servicename)

	#!/usr/bin/env python
	# Impacket - Collection of Python classes for working with network protocols.
	#
	# Copyright Fortra, LLC and its affiliated companies
	#
	# All rights reserved.
	#
	# This software is provided under a slightly modified version
	# of the Apache Software License. See the accompanying LICENSE file
	# for more information.

	#!/usr/bin/python3
	from __future__ import division
	from __future__ import print_function
	import re
	import codecs
	import logging
	import time
	import argparse
	import sys
	from impacket import version

	#ifndef PATCHLESS_AMSI_H
	#define PATCHLESS_AMSI_H

	#include <windows.h>

	static const int AMSI_RESULT_CLEAN = 0;

	PVOID g_amsiScanBufferPtr = nullptr;

	unsigned long long setBits(unsigned long long dw, int lowBit, int bits, unsigned long long newValue) {

	#include <Windows.h>

	LONG SingleStepEncryptDecrypt(EXCEPTION_POINTERS* ExceptionInfo);
	typedef VOID(__stdcall* Shellcode)();

	LPBYTE ShellcodeBuffer;
	ULONG_PTR PreviousOffset;
	ULONG_PTR CurrentOffset;
	ULONGLONG InstructionCount;
	DWORD dwOld;

	using System;
	using System.Collections.Generic;
	using System.Runtime.InteropServices;
	using System.Text;

	namespace Hollowing
	{
	public class Loader
	{
	public static byte[] target_ = Encoding.ASCII.GetBytes("calc.exe");

	set context persistent nowriters
	add volume c: alias someAlias
	create
	expose %someAlias% z:
	exec scriptfile.cmd
	delete shadows volume %someAlias%
	reset
	exit