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Displaying posts with tag: injection (reset)
SQL injection in the MySQL server (of the proxy kind!)

As work on WarpSQL (Shard-Query 3) progresses, it has outgrown MySQL proxy.  MySQL proxy is a very useful tool, but it requires LUA scripting, and it is an external daemon that needs to be maintained.  The MySQL proxy module for Shard-Query works well, but to make WarpSQL into a real distributed transaction coordinator, moving the proxy logic inside of the server makes more sense.

The main benefit of MySQL proxy is that it allows a script to “inject” queries between the client and server, intercepting the results and possibly sending back new results to the client.  I would like similar functionality, but inside of the server.

For example, I would like to implement new SHOW commands, and these commands do not need to be implemented as actual MySQL SHOW commands under the covers.

For example, for this blog post I made a new example command called “SHOW PASSWORD

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SQL Injection with MySQL SLEEP()

Recently we’ve received an alert from one of our clients that running threads are high on one of their servers. Once we logged in, we noticed that all the selects were waiting for table level read lock. We scrolled through the process list, and found the selects which were causing the problems. After killing it, everything went back to normal.
At first we couldn’t understand why the query took so long, as it looked like all the others. Then we noticed, that one of the WHERE clauses was strange. There, we found a SLEEP(3) attached with OR to the query. Obviously, this server was the victim of a SQL injection attack.

What is SQL injection?

I think most of us know what SQL injection is, but as a refresher, SQL injection is when someone provides malicious input into WHERE, to run their own statements as well.
Typically this occurs when you ask a user for input, like username, but instead of a real name they give you a …

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Scary Words – Apparently

The US Department of Homeland Security (you know that fast growing entity that didn’t exist pre-2001, that no politician wants to be responsible for shrinking for fear of being blamed in case anything happens) has been forced to release their list of keywords they monitor. An article was published by the Daily Mail online: Hundreds of words to avoid using online if you don’t want the government spying on you

Relevance for this blog? Near the bottom, in the category “Cyber Security”, we spotted a keyword “Mysql injection”. How exciting!

Here’s a challenge for you: can you write an innocuous story containing as many words as possible from this list? You can post it as comment here. I will send the winner a copy of the “Manga Guide to Databases” book, which – …

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Dynamic de-normalization of attributes stored in key-value pair tables

Dear Kettlers,

A couple of years ago I wrote a post about key/value tables and how they can ruin the day of any honest person that wants to create BI solutions.  The obvious advice I gave back then was to not use those tables in the first place if you’re serious about a BI solution.  And if you have to, do some denormalization.

However, there are occasions where you need to query a source system and get some report going on them.  Let’s take a look at an example :

mysql> select * from person;
| id | name  | lastname |
|  1 | Lex   | Luthor   |
|  2 | Clark | Kent     |
|  3 | Lois  | Lane     |
3 rows in set (0.00 sec)

mysql> select * from person_attribute;
| id | person_id | attr_key      | attr_value | …
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Parse nasty XLS with dynamic ETL

Dear Kettle friends,

Last year, right after the summer in version 4.1 of Pentaho Data Integration, we introduced the notion of dynamically inserted ETL metadata (Youtube video here).  Since then we received a lot of positive feedback on this functionality which encouraged me to extend it to a few more steps. Already with support for “CSV Input” and “Select Values” we could do a lot of dynamic things.  However, we can clearly do a lot better by extending our initiative to a few more steps: “Microsoft Excel Input” (which can also read ODS by the way), “Row Normalizer” and “Row De-normalizer”.

Below I’ll describe an actual (obfuscated) example that you will probably recognize as it is equally hideous as simple in it’s horrible complexity.

Take a look at this file:

Let’s assume that this spreadsheet …

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How To Fight Clickjacking (Using The Recent Twitter Hijacking As An Example)


Clickjacking is a malicious technique of tricking web users into revealing confidential information or taking control of their computer while clicking on seemingly innocuous web pages. A vulnerability across a variety of browsers and platforms, a clickjacking takes the form of embedded code or script that can execute without the user's knowledge, such as clicking on a button that appears to perform another function (credit: Wikipedia).

Clickjacking is hard to combat. From a technical standpoint, the attack is executed using a combination of CSS and iFrames, which are both harmless web technologies, and relies mostly on tricking users by means of social engineering. Additionally, the only server side technique against …

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Showing entries 1 to 6