CVE-2021-44147: XML External Entity Vulnerability in Claris FileMaker

A couple of months ago I looked more deeply into the “Import Records” functionality in FileMaker, especially the XML parsing, and was wondering if any XXE vulnerability may exist and how one could exploit this in technically interesting ways. The vulnerability is/was indeed there and can lead to local file disclosure and server side request forgery in various components of the FileMaker platform. The following is a description of the vulnerability including potential exploitation paths. ...

November 18, 2021 · David Hamann

CRTP Certification Review

A couple of days ago I took the exam for the CRTP (Certified Red Team Professional) certification by Pentester Academy. In this review I want to give a quick overview of the course contents, the labs and the exam. Course Contents Attacking and Defending Active Directory is the accompanying course for the CRTP certification and it covers – as the name suggests – various common attack vectors and persistence techniques in Windows AD networks. The course also gives an overview of the defensive measures you can take – from more high-level explanations of privilege separation models to deploying decoy objects in the environment for deception. ...

December 25, 2020 · David Hamann

Hack the Box Write-up #10: Buff

This is a write-up of today’s retired Hack The Box machine Buff. Buff was a fun 20 point box that included exploitation of a known vulnerability in a gym management web app and a classic buffer overflow for getting an administrator shell. In my opinion doing this machine can also serve as a good practice if you plan on doing something like the OSCP or eCPPT certification and still need practice targets for the binary exploitation / buffer overflow part. ...

November 21, 2020 · David Hamann

Hack the Box Write-up #9: Tabby

This is a write-up for Hack the Box’s just retired Tabby machine. We first find a Directory Traversal vulnerability in a web app and use it to obtain credentials for a Tomcat server running on the same host. Cracking a zip password of a discovered file then gives us access to the first low-priv user. From there, we exploit the fact that our user is part of the lxd group, create a small Alpine Linux image and eventually mount the host’s root file system in a new container. ...

November 7, 2020 · David Hamann

Hack the Box Write-up #8: Fuse

I finally found some time again to write a walk-through of a Hack The Box machine. In this post we’ll hack into Fuse, a Medium machine which just got retired and included some password guessing, discovery of stored plaintext credentials and eventually a SeLoadDriverPrivilege escalation. Recon and Enumeration To get a first overview of the box, we’ll start with a nmap -sC -sV 10.10.10.193. PORT STATE SERVICE VERSION 53/tcp open domain Simple DNS Plus 80/tcp open http Microsoft IIS httpd 10.0 | http-methods: |_ Potentially risky methods: TRACE |_http-server-header: Microsoft-IIS/10.0 |_http-title: Site doesn't have a title (text/html). 88/tcp open kerberos-sec Microsoft Windows Kerberos (server time: 2020-10-30 22:31:39Z) 135/tcp open msrpc Microsoft Windows RPC 139/tcp open netbios-ssn Microsoft Windows netbios-ssn 389/tcp open ldap Microsoft Windows Active Directory LDAP (Domain: fabricorp.local, Site: Default-First-Site-Name) 445/tcp open microsoft-ds Windows Server 2016 Standard 14393 microsoft-ds (workgroup: FABRICORP) 464/tcp open kpasswd5? 593/tcp open ncacn_http Microsoft Windows RPC over HTTP 1.0 636/tcp open tcpwrapped 3268/tcp open ldap Microsoft Windows Active Directory LDAP (Domain: fabricorp.local, Site: Default-First-Site-Name) 3269/tcp open tcpwrapped Looking at the ports and enumeration output, we can tell we’re dealing with a domain controller. ...

October 31, 2020 · David Hamann