CVE-2021-38647 – Open Management Infrastructure (OMI) RCE – Linux…

Situation

Ok so the situation is as per usual a bit fluid, when this first dropped I was looking at this with a “azure” lense, however as time goes on it appears this likely also covers any Linux distro with the Azure/SCOM/OMS agents installed. This may change the profile of risk considerable, not only from a public facing attack surafce but highly likely from a lateral movement persspective. I’m going to keep updating this as more intel comes in. (sorry I’d be clearer if I had a clearer picture myself)

This week 4 vulnerabilities were disclosed which affect ~~Azure~~ virtual machines running the Open Management Infrastructure (OMI) agent (think PowerShell remoting). As above the scope seems to be slightly wider with regard to SCOM/AZURE and OMS/Sentinel etc. agents for Linux (I want to confirm all of this but for now it seems this is the position)

Essentially these vulnerabilities allow for both network-based remove code execution (RCE) and local privilege escalation (LPE).

There is evidence of exploitation in honeypots.
There is a public proof of concept available for the RCE.
The internet facing attack surface from a global perspective seems low based on the data in Shodan and Censys however I’m not convinced this is currently giving a clear picture.
- So, check your azure networks, Vms and firewalls would be a sensible idea

CTF

Installing Kali 2021.3

Hax fun with the Dragon distro

Ok today we are going to look at deploying Kali 2013.3. The install process for this is fairly standard and familiar from previous version but for those new to this world, it seems like a good place to start.

Install Procedure (Virtual Machine)

Boot from the ISO

Read more “Installing Kali 2021.3” →

Guides

What if not everyone is a cyber expert?

Developing a Cyber Roadmap

Ok so this topic comes up a fair bit, but organisations and their management are often looking to ensure they are doing the right thing (no really this is a common phrase I hear with organisations) with regard to cyber security. THe challenge I think quite a few people have is even understanding what that even means. Sure you have a firewall, and antivirus and you had a yearly peneration test of a site that isn’t even touching your corproate network. You thought you were fine, but you keep seeing organisations get ransomared in the news and the board keep asking “are we ok?” so this then leads to a common position of maybe buying more widgets or thinking, well we haven’t been “hacked” so we must be doing ok.

Defense

Vulnerability Management – Actually doing it!

Vulnerability Management, Assessments and Vulnerability scanning is sometimes treated a with distain in the Offensive security community, I personally don’t understand that. Vulnerability management is key to inputting into security strategy, architecture, and operations. It’s coupled heavily to many other processes such as:

Asset Management
Risk Management
Patch Management
Change & Release Management
Security Testing
Security Monitoring

Before we start deploying let’s think about some areas for consideration when performing vulnerability scans:

Scope
- Asset/Hosts
  - IP Ranges
  - Hostnames
- Connectivity
  - VPNs
  - LAN/WAN
- Device Types and Configuration
  - Domain
  - Workgroup
  - Appliance
  - ICS
  - Printers
  - Network Equipment
- Unauthenticated View
- Authenticated View
  - Auth Types
  - Protocols
- Scheduling
- Authority to execute
Impact
- Performance
- Availability
- Confidentiality
Objectives and Outcomes
Reporting
- Information Flow
- Report Storage and Confidentiality

CTF

Abusing AdminSDHolder to enable a Domain Backdoor

If we have high privilege access to a domain, we will likely want to establish persistence with high privilege access. One mechanism to do this is to assign ourselves permissions to the adminSDHolder object in active directory:

Here we have the default adminSDHolder permissions. We are going to add our user “low” in here with modify or full control permissions: Read more “Abusing AdminSDHolder to enable a Domain Backdoor” →

CTF

How to Identify Hashes

Some hashes are obvious but even then, it’s a good job to check. There are a few ways to check a hash outside of manual validation.

Using the Hashcat example list:

https://hashcat.net/wiki/doku.php?id=example_hashes

Using hash-identifier:

https://github.com/blackploit/hash-identifier

Using cyberchef Analyse hash:

https://gchq.github.io/CyberChef/#recipe=Analyse_hash()

Using hash-id:

https://github.com/psypanda/hashID

Using HashTag:

https://github.com/SmeegeSec/HashTag

As you can see there are range of tools available to you, and remember if you want to keep the hashes to yourself you can download Cyberchef and run it locally!

Guides

Cracking an SSH key with John the Ripper (JTR)

This is a super-fast blog to show how to crack sshkeys with JohnTheRipper from Kali VM.

Create a key

Defense

Razer Privilege Escalation Vulnerability

“And I looked and behold a pale horse: and his name that sat on him was Death, and Hell followed with him.”

Firstly, Kudos to @j0nh4t for finding this!

I woke up this morning to see twitter fun with a LPE discovered in the Razer driver installation. Basically, when you plug a Razer mouse into a Windows machine, it will download (via windows update) and execute a process as system which has user interaction. This interface includes an install path selector, with this a right click + SHIFT (LULZ) on whitespace will allow you to launch a command prompt/PowerShell window (as SYSTEM).

Guides

Rapid Active Directory Security Testing of Windows Server 2022…

Introduction

Ever needed to test active directory in a hurry? Well, here’s some common commands to test active directory domain services. In this post today we are going to focus on DNS and username enumeration, there are however a range of weaknesses you want to look for:

SMB Null Session/Guest Access
LDAP Null Bind
Sensitive Information Disclosure
Weak Password Policies
Unpatched Software Vulnerabilities

Active Recon

Port Scanning and Service Fingerprinting

nmap -p- -sC -sV -Pn -v -A -oA ecorp.local.txt 192.168.1.22

Domain Name and Domain Controller Enumeation

Guides

Hacking Windows Server 2022

WIndows Server 2022 is RTM! I love new operating systems, but also with the new, what is old? There will be loads of new blogs and articles on new features of Server 2022 however I wanted to see what mischief we can have with it! So I’ve decided to start looking at common vectors and exploits (from the fun to the serious) so that we can see how much of the world has changed (or not!)

So let’s take a look. The first thing I did was to offline replace stickykeys with cmd.exe – yes this method still works. But as lots of people will realise, you neeed physical access to the disk (well you don’t if you have access to someone’s vcenter you don’t!) but also the reg key methods also work! We can still backdoor RDP – here’s a script to disable NLA, Enable RDP, configure the firewall rules and set the registry keys to backdoor the system (clearly for lab use only!)

https://github.com/mr-r3b00t/RDP_Backdoor