Archive for April, 2015

The Basics of Secure Web Development

The internet has contributed a great deal to commerce around the world in the last decade, and of course with a whole new generation of people breaking into the online world we’re starting to see just what computers are capable of accomplishing. Particularly when there is malicious intent on the other side of that keyboard.

Hackers and crackers are one of the biggest threats the world has ever experienced; they can take your money, your products or even destroy your business from the inside out – and you’ll never see them do it, they might not leave a trace at all. That is the terrifying truth about the internet; in most cases those with the skills to take what they want have the skills to hide themselves from detection – so what can you do to stop them.

The easiest way of protecting your website is to ensure that your business have a securely developed website. Secure web development is a complex area, and most likely something that you will need the help of a professional in order to fully implement, but it is worth noting that there are three different levels of security to take into consideration for your website and thus three different levels that need to be securely developed in order to ensure the protection of your business.

Consider these levels almost like doors. If your website was a business property you would have three ways in to the top secret bits; a front door, a side door and a back door.

The front door is the user interface; the bit of the website that you yourself work with. Now; the web developer might have made you a big magnificent door, lovely and secure – the sort of user interface that lets you manage your stock, orders, customers and all of the individual aspects of your business effortlessly without giving anything up. However; if your passwords aren’t secure it’s the equivalent of putting a rubbish, rusty old lock on that lovely secure door – completely pointless and insecure. Easy access. This is the first place a hacker is going to look – why would they waste their time hunting down and trying to exploit tiny weaknesses in the back door if they could open the front door with one little shove?

Change your passwords regularly, select passwords that use upper case, lower case, numbers and punctuation. Do not use the same password for everything.

The side door is the programming. The code used to construct your website puts everything in place and says who can do what and when; everything is controlled with the code, so an opening here can cause big problems if a hacker finds it. There are a number of different potential security risks when it comes to the code; there are bugs, which are just general, little faults with the website that occur when something didn’t go quite as planned or something was missed in the development stage. They always happen and there isn’t a single piece of software that doesn’t have bugs, the secure ones are just those that resolve the bugs as soon as they’re found, which stops them from being exploited.

Another risk to that side door is an injection; sort of like a fake key. This is something some of the smarter hackers can accomplish by injecting their own instructions into your system when it sends off a command or query – they can intercept your command or query. For example; let’s say you perform a simple PHP query that will fetch the products from the database when your user selects a product category. Normally this sort of script would be accessed through the URL with a category id.

For example;

Let’s say you did a regular sql database select query looking for the category ID, your category information and URL command might look something like;

c.category_id = ‘ . $_GET[‘cat’] . ‘LIMIT 10’;

Now; obviously this example suggests that the clever programmer has included a limit to prevent what is going to happen next – but this won’t protect him. Poor clever programmer is about to be outsmarted.

First of all; the only thing the thing the hacker needs to do is find your product list page and look for everything, example;

Yourwebsite.com/productlist.php?cat=1 or 1=1-

Doesn’t look like anything special right? Well, with this alone the hacker can now see every single one of your products. Depending on how secure your website is this might let them find faults in the products, but it’s probably still not that dangerous right? Well, what if they did this;

/productlist.php?cat=1 or error!;#$

Yep – bet you’re horrified now, because this will typically reveal the DBMS version of the query, and sometimes expose your table and column names. Not dangerous enough for you? With the tables and columns are revealed the hacker can move on to attacking the user table, all thanks to exploiting a weakness in the products table.

/productlist.php?cat=1 and (select count(*) from users) > 0

Creating a new query inside the existing one means that they don’t need to verify the database connection; they’re using yours. They have access to your database not and their using it to find your user table, which can progress to finding how many users you have, and even finding the information within the user table. I’m quite sure I don’t need to specify why having access to your user database is such a bad thing.

So – if you want to avoid the injections you need to ensure that every bit of input data gets validated, reduce the amount of information shown when an error displays, really limit the database permissions to prevent php queries from being able to pull any more information than they absolutely need to and use parameters in your queries.

Finally – the back door. This is the server. You need to ensure that the server you use to host your information and website is secure. There have been a number of cases where highly secure websites were eventually hacked by first hacking a much lower security website that shared the host server. If you want to avoid this you can consider a dedicated server for your website, you should also consider keeping to companies hosting companies that offer support and security as part of the hosting package. Ask them what software their servers are running; this will give you an idea of how regularly they are updated – up to date servers are the most secure. Older software has had longer to be exploited and thus more of the weaknesses in these are already known to hackers.

 

 

Kate Critchlow is a young and enthusiastic writer with a particular interest for technology, covering everything from secure development to the latest gadget releases.