Category Archives: Security

Logging more detailed data about websites blocked by NetScaler Web Application Firewall (WAF)

last update: April 16th 2018 I had been asked recently: Johannes, how can we log data about NetScaler Application Firewall policy hits in detail? The standard NetScaler Web Application Firewall log-files NetScaler’s Web Application Firewall logs to /var/log/ns.log. These logs are fine for trouble shooting. There is a good description… Read more »

Citrix NetScaler as a SAML IDP and SAML SP

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I needed to use a Citrix NetScaler both, as a SAML identity provider (IDP) and service provider (SP). So I set up my test environment accordingly. What my test environment looked like: You see, I created two admin partitions on my Citrix NetScaler, one for the service provider (SP partition),… Read more »

Digging into Citrix NetScaler IP-reputation feature

last update: 2018/04/12 I recently had to protect a website using IP reputation feature. There is some good information about this feature, however I decided to glean information here. Facts about this feature IP reputation is a platinum feature. It is included in web application firewall (there are extra licenses… Read more »

DDOS protection using Citrix NetScaler, 2nd part

Yesterday I published a blog about DDOS- protection. I used the Citrix NetScaler AppQoE feature to do so. That’s nice, but not enough. I still could beat my server to a pulp easily. Just 10 clients launching a DDOS attack using HULK had been enough. I can’t throttle down the… Read more »

DDOS protection using Citrix NetScaler, 1st part

last update: February 21st 2018 How to protect a website using Citrix NetScaler? Well it seems to be easy. A nonsense question. We may use AppQoE (Application level Quality of Experience), a feature introduced with NetScaler version 10, so it’s quite an old feature. Let’s start. AppQoE is enterprise edition… Read more »

Splitting up a NetScaler site using admin partitions

(a nice but partly failed try) Complex web applications may lead to complex NetScaler configuration. And sometimes an administrator may get lost troubleshooting complex websites, especially sites using content switching. This is an example of a real world website: The portal page is assembled of several independent web applications. Each… Read more »

Changing my Citrix NetScaler VPX based website from http to https and scoring an A+ in SSL labs test

Last update: February 7th 2017 Citrix NetScaler load balancing and content switching servers will only score an C in quality labs SSL test, no matter if you use a VPX, MPX or SDX. There are several reasons for this. You could probably say, Citrix is to be blamed for this, but… Read more »

How to get a valide certificate for our NetScaler, if possible for free?

This is an updated blog entry. I first posted it on my old and discontinued blog at blog.com for Citrix NetScaler 10, this one is for Citrix NetScaler 11. We all know how to get a private Certificate for free: You just have to set up a Windows Server, add… Read more »

Making a NetScaler Gateway on NetScaler 11 a bit more secure

last update February 7th 2017 We have previously created a NetScaler Gateway on our NetScaler 11. That’s great! Time to check if it’s secure. I usually use SSL labs SSL test, a widely used tool to test the security of a website. I have an other blog about NetScaler virtual… Read more »

Enabling ECDHE ciphers in NetScaler 10.5

last update: February 7th 2017 Similar but newer posts: Changing my Citrix NetScaler VPX based website from http to https and scoring an A+ in SSL labs test and Making a NetScaler Gateway on NetScaler 11 a bit more secure ECDHE Ciphers, this means, Elliptic curve Diffie–Hellman type of cyphers,… Read more »

Replacing HTTP server related information using a NetScaler policy label

It may not be the strongest security measure, but many administrators are not quite sure about HTTP headers like Server or X-Powered-By. There seems to be just one reason why this header has to be in a HTTP response: It makes life easier for a hacker. So why not just… Read more »

Hacking nsroot

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Hacking nsroot on a NetScaler with default settings is completely easy! I missed this one in Neil Spelling’s excellent blog about penetration testing NetScalers. What do you need to hack a NetScaler if you forgot your nsroot password? An external authentication source. How does NetScaler authentication work? Well, NetScaler will… Read more »