Research and Development

Portcullis Labs


Portcullis Labs is the R&D arm of Cisco’s Security Advisory team in EMEAR.

We built this web site to share some of our knowledge. You’ll find several tools, papers and presentations mostly by security geeks, but all for security geeks.

For more information about Cisco’s Services, please visit our corporate web site to get more information.

Recent Content


  • An offensive introduction to Active Directory on UNIX (12/6/2018) -
    By way of an introduction to our talk at Black Hat Europe, Security Advisory EMEAR would like to share the background on our recent research into some common Active Directory integration solutions. Just as with Windows, these solutions can be utilized to join UNIX infrastructure to enterprises’ Active Directory forests. Background to Active Directory integration […]
  • Where 2 worlds collide: Bringing Mimikatz et al to UNIX (12/6/2018) -
    Presentation on Active Directory integration solutions for UNIX (as given at Black Hat Europe 2018). Over the past fifteen years there’s been an uptick in “interesting” UNIX infrastructures being integrated into customers’ existing AD forests. Whilst the threat models enabled by this should be quite familiar to anyone securing a heterogeneous Windows network, they may […]
  • The importance of logs: You won’t see what you don’t log (10/31/2018) -
    Presentation on logging and auditing strategies (as given at Secure South West 11). Building on my blog post on Cisco’s security blog entitled The Importance of Logs, I put together a presentation that picks apart some of the practical aspects of building a successful logging capability focusing on the need to document “good” and curate […]
  • SetUID program exploitation: Crafting shared object files without a compiler (10/31/2018) -
    In this post we look at an alternative to compiling shared object files when exploiting vulnerable setUID programs on Linux. At a high level we’re just going to copy the binary and insert some shellcode. First we take a look the circumstances that might lead you to use this option. Also check out this previous post […]
  • Playback: A TLS 1.3 story (8/13/2018) -
    Presentation on 0-RTT in TLS 1.3 (as given at DEF CON 26 and Black Hat 2018). TLS 1.3 is the new secure communication protocol that should be already with us. One of its new features is 0-RTT (Zero Round Trip Time Resumption) that could potentially allow replay attacks. This is a known issue acknowledged by […]
  • Playback: A TLS 1.3 story (8/8/2018) -
    Secure communications are one of the most important topics in information security and the Transport Layer Security (TLS) protocol is currently the most used protocol to provide secure communications on Internet. For example, when you are connecting to your online banking application, your favorite instant message application or social networks, all those communications are being […]
  • Grabbing firmware from my cheap STM32-based magstripe reader (using ST-Link v2) (7/20/2018) -
    In my previous post, I worked around the fact that the card reader could only read credit cards – when I wanted to read other types of magstripes. I’d thought at the time that it would theoretically be possible to replace the firmware. In this post I don’t get as far as writing new firmware, […]
  • Reading hotel key cards with a credit card magstripe reader (7/4/2018) -
    In this post I describe how my cheap magstripe reader wouldn’t read all magstripes, only credit/debit cards. This did nothing to help me understand what data was on my hotel key card – which is what I really wanted to know. Rather than take the obvious next step or buying a better reader, I opted […]
  • Exploiting inherited file handles in setUID programs (6/28/2018) -
    In this post we look at at one of many security problems that pentesters and security auditors find in setUID programs. It’s fairly common for child processes to inherit any open file handles in the parent process (though there are ways to avoid this). In certain cases this can present a security flaw. This is […]
  • Adventures in RF: Using Inspectrum to analyse FSK and ASK/OOK signals (4/6/2018) -
    In this post we’ll take a brief look at inspectrum, a graphical tool for analysing signals captured via software defined radio (SDR) receivers – like the RTL-SDR or HackRF One. We’ll run through two examples of viewing digital signals. The first uses frequency shift keying (FSK). The second uses amplitude shift keying on-off keying (ASK/OOK). These […]
  • JTAG on-chip debugging: Extracting passwords from memory (3/29/2018) -
    Following on from my colleague’s post on using UART to root a phone, I look at another of our challenges, whereby sensitive information such as passwords can be extracted from a device’s memory if physical access to the device is acquired. The goal and target The target device is the BroadLink RM Pro universal remote […]
  • UART Debugging: Rooting an IP Phone using UART (3/23/2018) -
    In this post I share my solution to an internal hacker challenge relating to identifying the UART pins on a VOIP phone and using them to gain root access. UART (Universal Asynchronous Receiver-Transmitter) is a hardware device that is used for serial communications. It comes in the form of a physical circuit or as a […]
  • Hardware hacking: How to train a team (3/9/2018) -
    This is the first in a proposed series of blog posts that plan to give an insight into the ways we devised to train up our team in hardware hacking tools and techniques. This first post acts as an introduction to the regime to show off each of the challenges we set up to train […]
  • Secrets of the motherboard (2/16/2018) -
    Presentation on “interesting” features of the Intel x86[_64] platform (as given at 44CON 2017). A lot of recent work has gone into the discovery, analysis, and (on occasion) marketing of hardware weaknesses in the Intel x86[_64] platform particularly with respect to how it is often implemented as part of specific motherboard designs. Some, such as […]
  • Keep your cookies safe (part 2) (2/15/2018) -
    In the first blog post we talked about the dangers that your cookies are exposed. Now it is time to keep your cookies safe. Time to know what protection mechanisms there are, how to use them and why. How to read this post? The flowchart below will guide you to the process to check if […]

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