14 Jul 10 Securing PHPMyAdmin and SQL

PHP is of course a valuable tool, and PHPMyAdmin is an equally valuable asset for those that don’t like command line administration. The problem is that because it’s a valuable tool, it’s a security exposure. As a website security consultant, I see the problem often: people don’t secure the one thing that, if accessed by a malicious party, can give carte blanche for destruction.

One simple way to secure your installation is to slightly modify your config.inc.php file:

Look for this line:

$cfg['Servers'][$i]['auth_type'] = ‘config’;

Change “config” to “http”. By doing this, you will require that the database information (username and password) be entered prior to accessing PHPMyAdmin. Of course, this only addresses attacks over the web. If someone tries to remotely connect to your database and knows the root password, or the credentials for any of your database, then you’re still vulnerable.

One way to address the security of your config.inc.php file is to secure the directory that it’s stored in. This is especially important if you should be on a shared server.

Of course, there is still the matter of your SQL port, 3306, being open to remote attacks. The solution to this problem can be found in the /etc/my.cnf file.

You need to add this line to make it so that only your server can connect to the SQL server.

Ensure that it’s under the “[mysqld]” section:

bind-address = 127.0.0.1

This sets it so that the SQL daemon only listens for connections locally, i.e. on your server. Anyone who tries to connect remotely will be denied. Now, the argument could be made that you could also try to add “skip-networking” to your my.cnf file, and then specify the path to your socket file, but you still need a way to administer your SQL, preferably via SSH. By adding the “bind-address” command, you can do just that.

The name of the game is security, and assumption. You have to assume that everyone’s out to attack you. If you think like that, you’ll narrow down all the ports that are exposed, and secure your server. Your SQL server is, like your DNS server, vital. It most likely powers your site. If the database is attacked, the damage can be considerable. Do understand that if a hacker is intent enough, they will find a way in, but by making it as difficult as possible, you reduce the chances of that happening.

Tags: attacks, MySQL, PHP, php programmer resume, phpmyadmin, sql, website security consultant

24 Jun 10 PHP, MySQL and memcached

According to memcached is a distributed object memory caching system. It can be used to set and get data by keys by any application that supports sockets.

As a website security consultant I advise you to ensure that your memcache server runs on 127.0.0.1 only and that you secure your server. Anyone with access to the server can telnet to the server’s local interface and get/set your memcache data.

I’ve used memcached for a number of PHP/MySQL projects, where I want greater cache control on database queries, than just relying on MySQL’s inbuilt caching abilities.

Now, whilst memcached should not be used to mask bad database design and optimization, or badly written SQL queries, it can help dramatically with queries that simply take a long time and have already been optimized as far as possible.

Assume that you had a simple database query wrapper:
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Tags: memcache, memcached, MySQL, PHP

06 Jun 10 MySQL – Running Processes

Showing running processes is easy, just log in to the MySQL command line and issue ‘SHOW PROCESSLIST;’
mysql> SHOW PROCESSLIST;
+———-+——+————————-+————+———+——+———-+———————————————————————————————–+
| Id | User | Host | db | Command | Time | State | Info |
+———-+——+————————-+————+———+——+———-+———————————————————————————————–+
| 66041116 | root | localhost | NULL | Query | 0 | NULL | SHOW PROCESSLIST |
| 66042322 | sql | www.adamsinfo.com:57281 | websonline | Query | 1 | Updating | UPDATE `video_tags` SET `quantity` = ’27′ WHERE CONVERT( `tag` USING utf8 ) = ‘sport’ LIMIT 1 |
+———-+——+————————-+————+———+——+———-+———————————————————————————————–+
2 rows in set (0.00 sec)

You can also use 'SHOW' to display a wide range of information: http://dev.mysql.com/doc/refman/5.0/en/show.html

Tags: MySQL, processes, processlist, show

19 Jan 10 Website Security Scan

Websites get hacked every day, customers details taken, and it’s usually REALLY EASY to do. As a security consultant,  I often get a call after a Google search turns up with my details as the guy to contact when this happens.

Shameless plug: Why not contact me BEFORE this happens for a FREE basic web scan.

Shameless plug over, why not consider some of the things that can be done to help prevent a website breach..
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Tags: Apache, backups, code, cookie, cross site scripting, htaccess, LAMP, logs, mod_security, MySQL, PHP, php security, rate limit, restrict limit, Security Consultant, session, sniffing, sql injection, website security scan, xss

17 Dec 09 PHP Programmer – Logical Operators

PHP allows the use of boolean operators.

AND, OR, XOR and NOT. We can combine NOT with AND and OR to form the NAND and NOR operators respectively.

$a = ($b and $c); will return TRUE if both $b AND $c are TRUE, otherwise, it will return FALSE. This can also be specified as $a = ($b && $c)

$a = ($b or $c); will return TRUE if $b OR $c are TRUE, otherwise, it will return FALSE. This can also be specified as $a = ($b || $c);

$a = ($b xor $c); will return TRUE if $b OR $c are TRUE, but not if they are both TRUE, otherwise, it will return FALSE.

$a = (! $b); will return TRUE if $b is NOT TRUE.

$a = (!($b && $c)); will form NAND (NOT + AND)
$a = (!$b || $c)); will form NOR (NOT+AND);
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Tags: and, bool, boolean, logic, logical operators, nand, nor, or, PHP, php programmer, xor

05 Nov 09 PHP Developer – Looping through database results

As a PHP Programmer, a very routine PHP/MySQL procedure is fetching a set of records from the result of a query.

$sql = "SELECT ...";
$result_set = mysql_query($sql);
for ($ctr = 0; $ctr < mysql_numrows($result_set); $ctr++)
{
    $my_object = mysql_fetch_object($result_set);
    //do something with $my_object
}

Now as tidy as the above code is, what’s the big problem? The number of rows returned by the query remains the same throughout. Why are we calling the mysql_numrows function on the same result set, to return the same answer over and over, possibly thousands of millions of times depending on the size of the result set? On a larger web application with a larger result set, things like this will dramatically increase unnecessary overhead. This is one of the most basic optimizations to make:

$sql = "SELECT ...";
$result_set = mysql_query($sql);
$result_num = mysql_numrows($result_set);
for ($ctr = 0; $ctr < $result_num; $ctr++)
{
    $my_object = mysql_fetch_object($result_set);
    //do something with $my_object
}

Now, there’s a couple of different methods you can use to achieve the same purpose, some of which may actually be more appropriate, such as a simple while loop, but the purpose of this article was to illustrate the issue above solely. More on optimization later..

Tags: for, loop, MySQL, PHP, php programmer, sql

13 Oct 09 Copy/Export MySQL User Priviledges

I’m often asked how to copy or export MySQL Users from one machine to another. The following SQL query will show your users:

SELECT DISTINCT CONCAT (‘show grants for `’, user, ‘`@`’, host, ‘`;’) AS query FROM mysql.user;

In my case on my test server, this shows:

SHOW GRANTS FOR ‘root’@’127.0.0.1′;
SHOW GRANTS FOR ‘debian-sys-maint’@'localhost’;
SHOW GRANTS FOR ‘root’@'localhost’;

Now, I’ll need to execute each one of these as separate statements. The output of SHOW GRANTS FOR ‘root’@'localhost’; is:

GRANT ALL PRIVILEGES ON *.* TO ‘root’@'localhost’ IDENTIFIED BY PASSWORD ‘*XXX…XXX’ WITH GRANT OPTION;

Copy and paste each ‘GRANT’ statement to your new SQL server, with the hashed password intact and you should be ready to go.

Tags: PHP MySQL Developer, sql

26 Sep 09 PHP MySQL Developer – A Freelancer in London

Being a Freelance PHP MySQL Application Developer based in London has some major advantages as I found out today. The majority of both mine and my firm’s work is conducted online. Video conferencing over Skype, code delivery over SVN (Subversion), and bug tracking through Basecamp. Once in a while though an opportunity for a site visit in or around central London/West End pops up, and, schedule permitting, I’ll more often than not be happy to accept.

My core focus is on web application development, and being London based, I’ve had a chance to work with some great Companies. I’m currently at the time of writing, spending a few hours per week overseeing and managing a team of developers rewriting a wireless hotspot provider’s intranet which is proving to be very challenging, and great fun.

For more information on what it is that I actually do in the PHP/MySQL field, please view my PHP MySQL Developer series!

Tags: MySQL, PHP, php mysql, PHP MySQL Developer, php mysql developer london

25 Sep 09 PHP MySQL Developer – Using MySQLi Prepared Statements to Avoid SQL Injection

I’m going to demonstrate a very short and simple method of avoiding SQL Injection at the SQL query level. You’ll need MySQLi support, on Debian you can apt-get install php5-mysql will contain everything that you need, and would be installed by default with your LAMP Installation.
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Tags: apt-get, bind, blob, double, execute, integer, MySQL, mysqli, mysql_real_escape_string, object oriented, oo, PHP, prepared statements, sql injection, string

17 Sep 09 How to Find and Replace data in MySQL

It’s really easy!

UPDATE mytable SET myfield = REPLACE(myfield, ‘replace this’, ‘with this’);

Take a backup of your database first!

Tags: find, MySQL, replace