Perl Module for Cisco Firepower Management Center API

I may have reinvented the wheel with this but I’ve started to write a Perl module for interacting with the Cisco FMC API using Perl. I say I may have reinvented the wheel because I didn’t check to see if someone else had already done this. I’ve published my module on GitHub. At the time of writing this, the module is at version 0.01. And as per the README right now

Using acme.sh For Certificate Management

Back in 2016 I wrote some notes on issuing and renewing certificates through Let’s Encrypt and using EFF’s CertBot to facilitate this. Today I revisited this after seeing acme.sh on OPNsense. What’s super impressive with acme.sh is that it’s a shell script. And it’s super easy to use. Installing acme.sh is simple. After following these instructions you’re all set. Note that acme.sh is installed in to $HOME. It’s not installed

Simple Next Generation Firewall Manipulation Leading to Data Exfiltration

I was asked to take over a project involving implementing some Next Generation Firewalls. In this particular case it was Cisco Firepower Threat Defense. I was told that these NGFWs are all singing, all dancing and given the cost of them you’d expect that and more. I was told they understand more than just Layer 3 meaning we can do things like write rules based on FQDN, allow traffic based

Building a ZeroTier Bridged Network

I was listening to a recent Packet Pushers Priority Queue podcast called Meet ZeroTier – Open Source Networking and decided to give ZeroTier a go, to see if it really worked as described. TL;DR: Yes it really does work as described! If you’re unfamiliar with ZeroTier I highly recommend listening to this podcast to understand why, what and how. If you’re unsure on the why, what and how, this blog post

Creating a Highly Interactive Honeypot With HonSSH

HonSSH is essentially an SSH proxy, acting like a Man-in-The-Middle attack. It sits between the attacker and a honeypot and proxies the SSH connections. By doing this it can log all interactions, spoof (rewrite) login passwords and even capture files downloaded by the attacker on to the honeypot for later analysis. Below is my topology: Configuring the Honeypot Server For the honeypot server (the server attackers will login to), I’m using Ubuntu 14.04

A Guide to Using Let’s Encrypt

Up until a few moments ago, I was using CAcert for all my certificate needs. A free service offering SSL/TLS certificates. The only issue with CAcert is that their Root Certificate is not included in all mainstream Operating Systems or browsers, meaning users will get a certificate error unless they choose to install the Root Certificate. But now Let’s Encrypt is on the scene. A free, open and automated certificate authority that is

Reviving an Acer Aspire One ZG5 Netbook

I was given an Acer Aspire One ZG5 (A110) and asked to try to update it. There were a few problems with it. Firstly, it was running Ubuntu 12.04 but the upgrade to Precise Pangolin had broken and wasn’t easily recoverable. Secondly, the battery appeared to be dead and wouldn’t charge. In addition I also found that a BIOS password (“user” and “supervisor”) had been set but the password wasn’t

Disabling WordPress XML-RPC and Banning Offenders With fail2ban

This isn’t something new. SANS ISC reported on this 2 years ago. The bad guys love anything that can be used in a reflection DoS and the WordPress XML-RPC functionality is a prime candidate. There are various ways to disable it, through WordPress plugins for example, or by hacking away at code. All of these are fine if you’re in control over what gets installed on the web server. In a shared

Cisco Two Armed VPN Concentrator and Default Route

Take the following scenario: You have a hub site. Branch (spoke) sites connect to the hub with a L2L IPsec tunnel. All traffic must traverse the tunnel (no local breakout to the Internet). At the hub, your VPN concentrator is separate from your firewall and runs in two armed mode. Where one interface is outside the firewall (public) to terminate the incoming tunnels and another interface is within a DMZ. As such

Banning Repeat Offenders With fail2ban

More and more I see fail2ban banning the same hosts repeatedly. One way to tackle this could be to increase the ban time but you could also have fail2ban monitor itself to find “repeat offenders” and then ban them for an extended period of time. Firstly, create a filter definition:

This will be used against the fail2ban log and will find any hosts that have been unbanned. We don’t want to