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Welcome!

I’m Koen . I live in Bruges (Belgium), a splendid medieval city also known as the Venice of the North.

I’m involved with computer security and I work as a freelancer in incident response, incident coordination, threat intelligence, vulnerability management and security best practices. Basically all tasks related to managing a CSIRT / CERT (Computer Emergency Response Team).

My main interests in computers are security, web applications (PHP, MySQL, Apache), system administration and free software.

This site hosts a blog and I have a photo collection at Flickr.

I also have a site with (outdated) Linux information.

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Latest posts

ipv6: Neighbour table overflow

One of my virtual machines hosted at Gandi had an excessive amount of error messages

The cause of this error message are the IPv6 router announcements that try to discover and configure the IPv6 neighbourhood. The excessive amount of messages were polluting the logs.

After contacting the Gandi helpdesk they provided insight on the cause of the error message and provided mitigations to prevent these type of errors. I had to update /etc/sysctl.conf withRead more.

The Apache Struts 2 Vulnerability and the Importance of Patch Management

I published an article on IBM Security Intelligence on The Apache Struts 2 Vulnerability and the Importance of Patch Management.

The post describes a vulnerability in Struts 2, a free, open source framework for creating Java web applications that allows attackers to execute arbitrary code.

Simplifying Risk Management

I published an article on IBM Security Intelligence on Simplifying Risk Management.

What is Shodan telling us about ICS in Belgium?

I have been using Shodan, “the world’s first search engine for Internet-connected devices”, since a long time. Recently I switched my free account to a membership account. A membership account allows you to do API queries with additional query filters (for example restricting search results to specific countries).

In this post I describe the results of querying the Shodan API for ICS (or related) devices in Belgium. These results are entirely based on what isRead more.

Hack of Polish Financial Supervision Authority and Polish banks

A couple of days back the financial sector in Poland was shocked by the news that the Polish financial supervision authority was hacked and was used as an attack vector to get access to other (mostly Polish) banks.

This is a very short summary with some IOCs (Indicator of Compromise) that you can use to check your logs and verify if you are affected.

Note that most of this information is composed from information foundRead more.