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Displaying posts with tag: network (reset)
Network attacks on MySQL, Part 4: SSL hostnames

In my previous blogs I told you to enable SSL/TLS and configure it to check the CA. So I followed my advice and did all that. Great!

So the --ssl-mode setting was used a few times as a solution. And it has a setting we didn't use yet: VERIFY_IDENTITY. In older MySQL versions you can use --ssl-verify-server-cert. Both turn on hostname verification.

The attack

Get any certificate which is trusted by the configured CA, this can for example be a certificate from a development machine. And use that with a man-in-the-middle proxy.

Then the client:

  1. Checks if SSL is uses (--ssl-mode=REQUIRED)
  2. Verify if the certificate is signed by a trusted CA (--ssl-mode=VERIFY_CA)

Both checks succeed. But the certificate might be for and the database server might be …

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Network attacks on MySQL, Part 3: What do you trust?

In my previous blogs I told you to enable SSL/TLS and force the connection to be secured. So I followed my advice and did forced SSL. Great!

So now everything is 100% secure isn't it?

No it isn't and I would never claim anything to be 100% secure.

There are important differences in the SSL/TLS implementations of browers and the implementation in MySQL. One of these differences is that your browser has a trust store with a large set of trusted certificate authorities. If the website you visit has SSL enabled then your browser will check if the certificate it presents is signed by a trusted CA. MySQL doesn't use a list of trusted CA's, and this makes sense for many setups.

The key difference is that a website has clients (browsers) which are not managed by the same organization. And for MySQL connections the set of clients is often much smaller are more or less managed by one organization. Adding a CA for a set of …

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Network attacks on MySQL, Part 2: SSL stripping with MySQL


In my previous blog post I told you to use SSL/TLS to secure your MySQL network connections. So I followed my advice and did enable SSL. Great!

So first let's quickly verify that everything is working.

So you enabled SSL with mysql_ssl_rsa_setup, used a OpenSSL based build or put ssl-cert, ssl-key and ssl-ca in the mysqld section of your /etc/my.cnf and now show global variables like 'have_SSL'; returns 'YES'.

And you have configured the client with --ssl-mode=PREFERRED. Now show global status like 'Ssl_cipher'; indicates the session is indeed secured.

You could also dump traffic and it looks 'encrypted' (i.e. not readable)...

With SSL enabled everything should be safe isn't it?

The handshake …

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Network attacks on MySQL, Part 1: Unencrypted connections


In a set of blog posts I will explain to you how different attacks on the network traffic of MySQL look like and what you can do to secure your systems againt these kinds of attacks.

How to gain access

To gain access to MySQL network traffic you can use tcpdump, dumpcap, snoop or whatever the tool to capture network packets on your OS is. This can be on any device which is part of the connnection: the server, the client, routers, switches, etc.

Besides application-to-database traffic this attack can also be done on replication traffic.


This allows you to extract queries and result sets.

The default password hash type mysql_new_password uses a nonce to protect against password sniffing. But when you change a password this will be sent accross the wire by default. Note that MySQL 5.6 and newer has …

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Network Traffic Analyzer with RaspberryPI

Motivation Melbourne just won the “most liveable city 2016”, the 5th time in a row. That’s awesome, but it comes with a price, and the one you’d think of: internet here sucks! Sounds weird, isn’t it? Well, one of the reasons Melbourne is such a great city, is it’s size, the amount of people in [...]


we use tcpcopy to make real traffic on our core systems. Many problems will be found in advance if we enlarge queries several times.


linux memory management for servers

We’ve been learning for many years how to run Linux for databases, but over time we realized that many of our lessons learned apply to many other server workloads. Generally, server process will have to interact with network clients, access memory, do some storage operations and do some processing work – all under supervision of the kernel.

Unfortunately, from what I learned, there’re various problems in pretty much every area of server operation. By keeping the operational knowledge in narrow camps we did not help others. Finding out about these problems requires quite intimate understanding of how things work and slightly more than beginner kernel knowledge.

Many different choices could be made by doing empiric tests, sometimes with outcomes that guide or misguide direction for many years. In our work we try to understand the reasons behind differences that we observe in random poking at a problem.

In order …

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Video Tutorial on Network Throttling tool provided by Google Chrome Developer tools

Network Throttling tool provided by Google Chrome Developer tools
In this video we will be seeing how this tool helps us to test your application at different network speeds, thus giving us info and insight as to how users having different speeds of internet use our application and the challenges they face and how the performance can be improved and how the application can be made more usable in such cases.

MySQL - basic network security

Having secured our MySQL server and created a personal account to allow for remote administration, we can take one step further on blocking unwanted access to our database server. For this example, we'll continue to use the Ubuntu 14.04.2 LTS Server installed and configured on the previous posts. After booting up the server, running a network check for connections, lists our server listening on

FrOSCon 10: Private Cloud mit OpenSource

Auf der FrOSCon 10 in St. Augustin habe ich kürzlich ein Update zu unseren Erfahrungen mit dem Thema "Private Cloud mit OpenSource" gegeben. Leider sind noch nicht alle Probleme, über die letztes Jahr berichtet wurde, behoben, aber wir sind schon ein gutes Stück weiter und haben neue Stolperfallen gefunden und z. T. auch überwunden.

Leider habe ich mich mit der Zeit ein wenig getäuscht, da ich den Talk vorher schon einmal in gekürzter Form in 40 Minuten unterbringen musste, aber in der Präsentation den Countdown für die FrOSCon wieder auf 60 Minuten zu stellen vergessen hatte. Zwischenzeitlich war ich deswegen der Meinung, ziemlich hinterherzuhängen... Hoffe, es macht trotzdem ein bisschen Spaß, so blieb am Ende mehr Zeit für Fragen und Gespräche :)

Hier noch die Folien auf Slideshare:

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