This post reviews how the Kerberos Bronze Bit vulnerability (CVE-2020-17049) can be exploited in practice. I strongly suggest first reading the Bronze Bit Attack in Theory post to understand why and how this attacks works. It is also worth noting that Microsoft published a patch for the vulnerability on November 10, 2020. The patch rollout […]
Introduction and Background This attack expands upon the excellent research documented by Elad Shamir in “Wagging the Dog: Abusing Resource-Based Constrained Delegation to Attack Active Directory.” I’ll cover the key points below, but his article a great resource and primer for Kerberos and constrained delegation in AD. If you’re already familiar with the Kerberos fundamentals, […]
With the release of Microsoft’s patch to fix CVE-2020-17049, I’m excited to share details about this vulnerability and how it could be exploited. This post is only a very high-level overview, and I strongly encourage readers who are interested to check out my follow-up posts which provide much more depth: To learn about Kerberos, Kerberos […]
TL;DR If you’re a local admin on an Azure VM, run the Get-AzureVMExtensionSettings script from MicroBurst to decrypt VM extension settings and potentially view sensitive parameters, storage account keys and local Administrator username and password. Overview The Azure infrastructure needs a mechanism to communicate with and control virtual machines. All Azure Marketplace images have the […]
PowerShell and Bash scripts are excellent tools for automating simple or repetitive tasks. Azure values this and provides several mechanisms for remotely running scripts and commands in virtual machines (VMs). While there are many practical, safe uses of these Azure features, they can also be used maliciously. In this post we’ll explore how the Custom […]