A few weeks ago I gave a presentation with the above title at some corporate infosec event. Given I’ve been asked for the slides many times now, I’ve converted them to a PDF which can be found here.
We hope to contribute to the necessary debate thereby…
Have a good one,
Enno
Continue readingSome of us had the pleasure to participate in this year’s Daycon VII, three days of Real Hacking and Relevant Content, in Dayton, OH. The event began on September 16th with the Packetwars bootcamp. We had the chance to teach some really promising young students and to prepare them for the Packetwars battle that was scheduled four days later. The students had to go through topics like Windows security, network security and web application security both practical and in theory.
Continue reading Continue readingDear readers,
today we welcomed Michael Ossmann at the ERNW headquarter for an exclusive workshop on his HackRF gadget. Everybody was quite excited to get hands-on with this shiny piece of hardware, which is currently crowd-funded on Kickstarter. For everybody who’s not familiar with Software Defined Radio (SDR): Let’s regard it as the ultimate tool when working with radio signals.
Michael Ossmann in the house.
Let’s quote Michael’s campaign website:
Transmit or receive any radio signal from 30 MHz to 6000 MHz on USB power with HackRF. HackRF is an open source hardware project to build a Software Defined Radio (SDR) peripheral.
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With HTML 5 the current web development moves from server side generated content and layout to client side generated. Most of the so called HTML5 powered websites use JavaScript and CSS for generating beautiful looking and responsive user experiences. This ultimately leads to the point were developers want to include or request third-party resources. Unfortunately all current browsers prevent scripts to request external resources through a security feature called the Same-Origin-Policy. This policy specifies that client side code could only request resources from the domain being executed from. This means that a script from example.com can not load a resource from google.com via AJAX(XHR/XmlHttpRequest).
Continue reading Continue readingI’m currently catching up on a lot of papers and presentation from the Usenix Security Symposium in order to finish the blog post series I started last week (summarizing WOOT and LEET). One presentation, which unfortunately is not available online [edit: see also update, videos are available now], included several particularly relevant messages that I want to share in this dedicated post. Chris Evans, the head of the Google Chrome security team (herein short: GCST), described some new approaches they employed for their security team operations, some lessons learned, and how others can benefit from it as well (actually the potential of these messages to make the world a safer place was my motivation to write this post, even though I got teased for supposedly being a Google fanboy 😉 ):
Continue reading Continue readingSUSE Linux Enterprise Server (SLES) has been around since 2000. As it is designed to be used in an enterprise environment the security of these systems must be kept at a high level. SLES implements a lot of basic security measures that are common in most Linux systems, but are these enough to protect your business? We think that with a little effort you can raise the security of your SLES installation a lot.
Continue reading Continue readingThis is the first part of an article that will give an overview of known vulnerabilities and potential attack vectors against commonly used Virtual Private Network (VPN) protocols and technologies. This post will cover vulnerabilities and mitigation controls of the Point-to-Point Tunneling Protocol (PPTP) and IPsec. The second post will cover SSL-based VPNs like OpenVPN and the Secure Socket Tunneling Protocol (SSTP). As surveillance of Internet communications has become an important issue, besides the traditional goals of information security, typically referred as confidentiality, integrity and authenticity, another security goal has become explicitly desirable: Perfect Forward Secrecy (PFS). PFS may be achieved if the initial session-key agreement generates unique keys for each session. This ensures that even if the private key would be compromised, older sessions (that one may have captured) can’t be decrypted. The concept of PFS will be covered in the second post.
Continue reading Continue readingContinuing yesterday’s post, I compiled a short summary of relevant WOOT’13 presentations.
Truncating TLS Connections to Violate Beliefs in Web Applications
Ben Smyth and Alfredo Pironti, INRIA Paris-Rocquencourt
This presentation was also given at BlackHat some weeks ago. It outlines a very interesting class of attacks against web applications abusing the TLS specification which states that “failure to properly close a connection no longer requires that a session not be resumed […] to conform with widespread implementation practice”. This characteristic enables new attack vectors on shared systems where certain outgoing (TLS encrypted) packets can be dropped in order to prevent applications from e.g. correctly finishing transaction (such as log out procedures) or even modifying the request bodies by dropping the last parts.
Continue reading Continue readingI have the pleasure to visit this year’s USENIX Security Symposium in Washington, DC. Besides the nice venue close to the national mall, there are also several co-located workshops. Every night I will try and provide a summary of those presentations I regard as most interesting. However, I hope to manage to keep up with it as there are a lot of interesting events, people to meet, and still some projects to keep up with. The short summaries below are from the 6th USENIX Workshop on Large-Scale Exploits and Emergent Threats.
Continue reading Continue readingA recent post describing some nasty vulnerabilities in HP multifunction devices (MFDs) brings back memories of a presentation Micele and I gave at Troopers11 on MFD security. The published vulnerabilities are highly relevant (such as unauthenticated retrieval of administrative credentials) and reminded me of some of the basic recommendations we gave. MFD vulnerabilities are regularly discovered, and it is often basic stuff such as hardcoded $SECRET_INFORMATION (don’t get me wrong here, I fully appreciate the quality of the published research, but it is just surprising — let’s go with this attribute 😉 — that those types of vulnerabilities still occur that often). Yet many environments do not patch their MFDs or implement other controls. As it is not an option to not use MFDs (they are already present in pretty much every environment, and the vast majority of vendors periodically suffer from vulnerabilities), let’s recall some of our recommendations as those would have mitigated the risk resulting from the published vulnerability:
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