Service principal names (SPNs) are records in an Active Directory (AD) database that show which services are registered to which accounts:
If an account has an SPN or multiple SPNs, you can request a service ticket to one of these SPNs via Kerberos, and since a part of the service ticket will be encrypted with the key derived from the account’s password, you will be able to brute force this password offline. This is how Kerberoasting works.
There is a way to perform the Kerberoasting attack without knowing SPNs of the target services. I’ll show how it could be done, how it works, and when it could be useful.
Openfire is a Jabber server supported by Ignite Realtime. It’s a cross-platform Java application, which positions itself as a platform for medium-sized enterprises to control internal communications and make instant messaging easier.
I regularly see Openfire on penetration testing engagements, and most of the time all interfaces of this system are exposed to an external attacker, including the administrative interface on 9090/http and 9091/https ports:
Since the Openfire system is available on GitHub, I decided to examine the code of this web interface. This is a short writeup about two vulnerabilities I was able to find.
During External Penetration Testing, I often see MS Exchange on the perimeter:
Exchange is basically a mail server that supports a bunch of Microsoft protocols. It’s usually located on subdomains named autodiscover, mx, owa or mail, and it can also be detected by existing /owa/, /ews/, /ecp/, /oab/, /autodiscover/, /Microsoft-Server-ActiveSync/, /rpc/, /powershell/ endpoints on the web server.
The knowledge about how to attack Exchange is crucial for every penetration testing team. If you found yourself choosing between a non-used website on a shared hosting and a MS Exchange, only the latter could guide you inside.
In this article, I’ll cover all the available techniques for attacking MS Exchange web interfaces and introduce a new technique and a new tool to connect to MS Exchange from the Internet and extract arbitrary Active Directory records, which are also known as LDAP records.
This is Big-IP, an application delivery and security services platform by F5 Networks, namely its Traffic Management User Interface (TMUI). In this article I will show how I’ve managed to discover CVE-2020-5902, an Unauthenticated Remote Command Execution vulnerability, in its web interface.
The CVE-2020-5902 vulnerability has been assigned a CVSS score of 10, the highest possible. According to the Threat Intelligence Services of Positive Technologies, before the fixes there were more than 8,000 devices available on the Internet and vulnerable to this issue.
Many of you have probably heard of the CVE-2019-19781 vulnerability that I discovered at the end of last year. It is a critical vulnerability in Citrix ADC that allows unauthorized users to execute arbitrary operating system commands.
It caused quite a stir when Citrix released its guidelines for addressing the vulnerability since approximately 80,000 companies from around the globe were threatened by the problem. Another reason why the vulnerability attracted so much attention because Citrix ADC is installed on the border between external and internal organization networks. Thus, when a hacker exploits the CVE-2019-19781 vulnerability, he or she simultaneously gains access to the targeted company’s internal network and is able to develop attacks on the private segment of the network.