Category Archives: Secure things

GDPR – The Forgotten Tests – Test 1

General Data Protection Regulation or GDPR is all about privacy. If a company handles privacy in the right way, then it can dodge penalties like 20 million Euro or 4 % of the worldwide revenue.

Time for a legal break. Right after this break some idea.


I am not a legal expert. So please have a look at my used sources. Or contact a GDPR expert.

I am just a tester finding test ideas about GDPR. Thanks for joining in advance.

The following story has been sanitised by me. Important details have been changed.

Bad idea

The job interview was about an agile tester. I thought I could handle that role. The probing questions from the interviewers were increasing. I tried to stay calm and answer the questions in a friendly way.

Then came the expected question about test cases. They should be written beforehand. Time to explore.
“You never know what you will find.”, I remarked.
“Let me give me an example.”

“Your company sent me this mailing.”
I showed a part of the mail.
“At the bottom of the mail I could say, whether I like this mail.”
There were two pictures: one green thumb up and one red thumb down. There was an orange arrow pointing to the thumb up.

“If I hover above the picture of the green thumb, the URL will be shown in the status bar of the mail.” The URL was contained in a red eclipse.

A sketch of a mail with an orange arrow pointing to a thumb up next to a thumb down. The mail also contains a URL in a red eclipse.

“As you notice: the URL is http. This is not secure. If the mail is intercepted, then the reaction of the customer can easily be determined. This is an email about credit, so you can derive that the customer probably has some debts.”

One of the interviewers politely interrupted me:
“Is it possible to intercept mail?”
I gave a technical answer using normal words.
Okay, I got his attention.

Then the exploratory tester awoke in me. And I could not stop him.
“There is a customer number in the mail. This number can be used to get access to an online account.”
I went in full brainstorm mode and described all kinds of product risks or things which could harm the user. I could find information about correspondence about money.

I didn’t get the job, but the mailing was fixed afterwards. Obviously 20 million Euros are not enough to qualify as a tester.

But there are retrospectives for.
[On the melody of ‘That’s What Friends Are For’.]


Most of the time primary systems were and are tested for GDPR and national privacy laws. Sometimes this software did not easily support mailings. An easy solution was to use another system outside the company. Specialised in mailings.

All kinds of data like email addresses, names, and profiles were used for mailings. Technical decisions were taken like http instead of https. Somehow the legal department and testers missed something.

According to GDPR the protection of personal data is a fundamental right [ (1) on page 1]. The economic situation of a person can be used for profiling. In turn this can be used to exclude people to get certain services like mortgage [ (75) on page 15].

My tips for testing:

  • become a customer of your own company and use all available channels. Watch for the legal details like the missing s of https. (See last tip)
  • follow security experts on social media. (You know about the last tip)
  • explain legal and security stuff in normal words.
  • let the owner control the flow of information. I should have send my brainstorm on request.
  • read  ‘Here’s Why Your Static Website Needs HTTPS’ by Troy Hunt, a security researcher. It contains an entertaining 25 minute video with several attacks on an http website.
    For people new to security, just watch the video and focus on what you would not like to happen on your website.

Closing note:
At the moment there are browsers showing whether a website is insecure. This was not the case, when I received this mailing.

To be continued.

Tweaking My Website Security

WordPress is frequently used for websites and therefore attractive to some unfriendly people. So I reconfigured my WordPress security plugin.
And the mails of failed logins started coming in. It was not me, so someone else wanted to use this web site.

A short history about my tooling

For me web site security is something to review on a regular basis. It all started with an article in a magazine.  I put some elementary stuff in place: limited number of log ins and removed the login from the web site.

Over the months I added extra stuff like SSL. It encrypts the traffic between the browser and my web site. In other words my user name and password are unreadable for interested bad guys
Troy Hunt mentioned SSL in his free web course with the haunting name: Hack Yourself First.  Cheers mate.
In case you missed it SSL can be obtained for free at Let’s Encrypt.

At a regular basis I updated the software for my web site. I thought I was quite good until I changed the settings.

A short note about security

Some people might complain about the default security settings of their web site settings. Believe me things can be improved. If you do not set the WordPress settings right, then the user name is shown instead of your writer’s name on the blog post. Luckily there are plugins. (As a Dutchman I could not ignore the free ones.)

I thought about the default security and try to explain to you. If I buy a house, it has standard locks. If I want to keep the baddies out, I have to use the keys.
There are no special keys and locks involved. In case I need them I have to change them.
My new house has no vault or armed guards. If I need them, then I have to change something.

Shorten my list of security mails

So I had changed something and security mails came into my mail box. I noticed that there were mails with wrong user names and passwords. Not good.

After a few days I expected them to stop. You know: “Oops wrong web site. Sorry for that.” But the flow of failed login attempts did not stop. So I had to change something. Again.

I remembered a firewall in one of my WordPress plugins, so I had my first taste of a firewall. Dry, not shaken.
I had IP addresses of the sources of attack. Courtesy service of one of my WordPress iplugins.
An IP address consists of 4 numbers separated by a dot (.) like the invalid 345 345.345 345.

So I put the most offending IP addresses on the black list.

Three strikes and you are out.

The brute force attacks continued. The following combinations were used:

table with failed login attempts

The  user name is in the heading and the password is  shown in the first column. More details about this teaser will be added in the appendix.

My action did not change the flow. I used the asterix. 345 345.345.*. All people coming from IP addresses starting with 345.345.345 got blocked.

Wrong zone. Offsite. Stop the game.

It looked like I had put oil on fire. My normal mails were somewhere between the security mails.

I also noticed that black listed IP addresses still passed through. So there were apperently some smart guys pick locking the door of my web site. I’ll add some words to this assumption  at the end.

It was time for harsh measures. I was so focused on the mails, that I skipped my notetaking. In my logs other URLs were mentioned.  I clicked on one containing wp-admin and noticed that I saw my login page.
I changed a name somewhere and the security mails did not come in any more. Phew.

Brief briefing about red teaming

My list of WordPress plugins would be quite interesting for the people who really want to block out the intruders. The main reason I do not list them is red teaming. This military term is like give my plan to the red team, who will misuse this knowledge to my full disadvantage. Did you notice that “full” sounds like “fool”?

My steps for red teaming of my web site:

  1. Install the web site with all plugins.
  2. Configure the web site and the plugins.
  3. Look at for any bugs.
  4. Misuse the listed CVE or Common Vulnearbilites  and Exposures.
  5. Go to the subdirectories and look for strange files.
  6. Look whether those files are accessible from the outside.

This reads like the plot of a bad B movie. But it works.

A short note about security

Some people might complain about their default website settings. Believe me things can be improved. If you do not set the WordPress settings right, then the user name is shown instead of your writer’s name on the blog post. Luckily there are plugin.

I thought about the default security and try to explain it to you. If I buy a house, it has standard locks. If I want to keep the baddies out, I have to use the keys.
There are no special keys and locks involved. In case I need them I have to change them.
My new house has no vault or armed guards. If I need them, then I have to change something.

Had a short glance

The days after the intentional reduction of my mail I had another look to my log files. My login page was requested several thousands times in a month. And I can assure you that I was not blogging so much.

There were other pages or URLs which led to my login page. So a check on the hits on my login page would give me the wrong impression of safety. There are people who do not like to use numbers or metrics. Some numbers can be really useful when pondered upon.

Somehow I had not paid attention. Too much focus on blogging. Obviously.

An article of Santosh Tuppad was quite helpful to increase the security. Thanks mate.

I even noticed that wp-content was open. So any pictures of draft blog posts could be viewed before publication. I even discovered a CSS file of a WordPress security plugin, which I could access without logging in. It was like finding a business card of a security team at the doorstep.

Wait a moment.

Let’s turn this into a multiple choice question.
What is the reaction of thieves on the business card?
A. Let’s skip this house.
B. I know how these guys operate. Piece of cake.
C. Look at the big bird and the shield of armor. That is pretty neat. We need 500 of those cards.

Definitely something for an action movie.

Some tips:

  • Read the reviews of the WordPress plugins.
  • Install WordPress plugins from the official site.
  • Write down, what works.
    Some plugins do not mix. This might be the cause of the strange behaviour of my firewall.
  • Make an offline copy of the website before tweaking.
  • Tweak the website security several times a year.
  • Go to your web site on a regular basis and install the updates.
  • Keep on an eye on Social Media.
    Troy and Santosh are great sources.
  • Basically, explore your web site security.

Appendix A bit of data crunching

For my first real life forensic investigation I wanted to use the gathered data. As in Data the Gathering. In order to process my e-mails I used baregrep, vim, Javascript, CSS, HTML.

People had attempted to break in my web site. I expected a concentrated set of failed attempts like
expected heat map

When I looked to the patterns I noticed this:
observed heat map
This is an example of a Blink Test. Lots of info processed in milliseconds and still getting useful info.


  • Combinations were entered once.
  • Combinations where user name was the same as the password were frequently used.
  • The same for combination with user name equal to admin


  • There is a high chance that a group tried to break in. There is a moderate chance that there were more groups which used different lists.
  • A popular user name is admin. See the first column.
  • Single words are favourite, followed by words and numbers.
  • Some user names and passwords were linked to my blog.
  • My blog posts are read.

daD Talk

One of the things I wanted to develop is critical thinking. Not only by myself, but also by my kids themselves. The led to a rather unpleasant start of one of those dad kid conversations.

There was no way back: a subject I tried to delay for a few years:
computer security.

The complaint about a program was packaged as a request:
“I want to have a computer, which can execute [dangerous module] programs without using [dangerous module].”

I exhaled. My kid had absorbed the information and realised that the use could have a severe consequence for the computer. No more computer time. On the other hand the disadvantages were too big to forget about it.

I tried to find a solution, but I could not find one. If a program can change things on a computer, then it can do bad things.

While blogging I realised I was wrong. There was a work around.
There are programs, which can do same things like the original program, but they are built differently. They are called emulators. Some gamers like to play low resolution games on emulators of very old operating systems.
Wow, that’s my kid.

It’s hammer time

“If you have a hammer, then you can use it to break a window. But that’s not right.”
My kid nodded.
“So I program the hammer, so it cannot be used for a window glass. Then I can go to a door and use it to break a lock. I can program it not to break a lock. Then I can use it for a window frame.”

It would be easier to tell the hammer it could only be used on wood. This looks brown and it has grains. But it could be changed, so that everything looks like wood.”
I made a wide gesture with my arm pointing to different objects in the room.

“But I could change the picture. All objects would look like wood. That is not a good idea, so I store the picture in a book. But the picture in the book can still be changed.

Then I could place a lock on it. But the lock could be picked. I could place a better lock on it, but then the whole book could be replaced by another book.

And that’s why it is so difficult to secure things.”

Another unpleasant guest
My kid had seen a cool app. And it should be installed absolutely. So I did my dad thing:  looking at the permissions, which I would grant to the app. It could handle my files. It was just a game and why should game have a peek at my files? Time for the bad news.

So I told my kid, that the app would access files on the phone. The reply was to buy a phone just for games. Then I told that after a while the phone would be also used for other purposes like making pictures. “You don’t want your pictures in someone else’s hands.” There was a lack of nod.

I needed another way to tell the warning. A visual one.
“Suppose someone comes in. He looks television for the whole evening. And he eats the whole fridge empty.

If you protest, he will say:
“You said I could come in.”

The next evening he comes back. He takes the table and the sofa out of the house.

If you protest, he will say:
“You said I could come in.”