Posts in Security & Compliance
Implementing a Content Security Policy
- 21 March 2023
Implementing a Content Security Policy (CSP) for a website can be a daunting and difficult task as it can break your website when done incorrectly. But a CSP can help to guard against cross-site script attacks and data injection attacks on a website as it defines which resources are all allowed to be loaded or executed. This also reduces the risk of including unauthorized third-party content to be included or posted to another site.
Configuring CSP can be done by adding a HTTP response header or by adding a META-tags to the requested HTML content. The latter depends on the CMS to be executed correctly for all HTML content requested. Most sites therefore implement the HTTP response header method as all the common web servers and content delivery networks support this.
Is CWE-525 still relevant?
- 28 April 2017
During a code upgrade for a web application from Symfony 2.8 to 3.3 it also became time to do some basic tests with Zed Attack Proxy. While most findings were logical and easy to fix, but one was different and it started with the finding below.
Description: The AUTOCOMPLETE attribute is not disabled on an HTML FORM/INPUT element containing password type input. Passwords may be stored in browsers and retrieved.
Kali Linux 2016.2
- 04 September 2016
Last week Kali Linux 2016.2 was released so it was time to make a new VirtualBox instance for it to see the difference from the release in January. But let’s automate a little bit to quickly rebuild virtual machines for Kali Linux.
Let’s create the virtual machine and boot it. In this example it is bound to the wireless network card and allocates an 16 GB disk image as the default 8 GB size for Debian is too small and 10 GB is the minimum advised.
Disabling SSLv3 in Apache
- 29 April 2015
Yesterday I wrote a post about disabling SSLv3 in Postfix and today we take a close look at Apache. While taking a closer look at the current installation of Apache and the version shipped with Debian 8 that was released a few days back it showed that the Apache project or Debian has taken the responsibility to completely disable SSLv2. Hopefully, SSLv3 will get the same treatment soon, as broken security is worse than no security due to a false sense of security.
After a clean install on Debian Wheezy
/etc/apache2/mods-available/ssl.conf contains the following entries:
Disabling SSLv3 in Postfix
- 28 April 2015
The POODLE attack was made public in late 2014 and most vendors have taken action to solve possible issues related to POODLE. The time definitely has come to close SSLv3 in all parts of the public-facing infrastructure. By default Postfix still only disallows SSLv2 and hopefully, this will change in the form of stricter default behavior in Postfix or distributions/vendors that stop shipping SSLv3 libraries.
For now, you can set with the
postconf command restrictions which protocols shouldn’t be used by Postfix.
Installing SSL certificates on Debian
- 28 January 2015
Installing and configuring SSL certificates is always an issue as to how to create them and where to store them. Most of the time people can find the procedure on how to create them, but they forget all the places where they have placed them. Some initiatives exist to have centralized key stores on systems, but getting applications to use them is still a problem.
Also on Debian is this an issue and key material is all over the system if youre not careful. Some Debian developers tried to fix it, but it ended in a “stalemate” and for now, an additional package called
ssl-cert exists to create self-signed certificates. This package also provides a structure for storing commercial certificates and accessing them in a safer way. We install the package
ssl-cert for this.