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Website Security Without Breaking the Bank?
An anonymous reader writes "I do my own Web design and have a few websites — MySQL, PHP, CSS, HTML, that kind of thing. It's simple, amateur stuff, but I would love to have some reasonable ways to assess their security myself and patch the big holes, or possibly enlist someone to do 'white hat' work to assist me. I have absolutely no idea how to proceed. I don't want to get mired in a never-ending paranoia-fueled race to patch holes before the hackers find them, but on the other hand, I don't want my websites to look like Swiss cheese. Right now, I wouldn't know what kind of cheese they look like: Swiss, Havarti, or hard as Parmesan. How can I take reasonable steps to protect these websites myself? What books has the community found useful? What groups (if any) can offer me inexpensive white-hat hacking that won't end up costing me a first-born child? Or am I better off just waiting until a problem arises and then fixing it?"
What's the URL? ;)
Buy a pony.
You still need to do homework. I realized a while ago that I not only lack a good understanding of potential weaknesses in my sites, but I also lack the knowledge needed to actually do the forensic log analysis if I was to actually get exploited. Along the lines of the original post, what good introductory tools are there that relate to forensic log analysis?
"Proximity to wonder has blunted our perception and appreciation of it" --Tim Hartnell in 'Exploring ARTIFICIAL INTELLI
http://www.owasp.org/index.php/Main_Page
You can write insecure websites using pretty much any tools, but if you're using MySQL and PHP, especially if you're using other peoples code in your app, you're probably going to end up with a security nightmare, regardless of how hard you try.
It's possible to write secure code in PHP, but almost nobody does, and most of the PHP code that you can acquire easily is painfully insecure. A never ending race to patch a never ending series of holes means you've already failed at security. Depending on "white-hat hacking", ditto.
Other than that... security is something integrated process, starting with the architectural design, the implementation and the processes around it, documentation and maintenance. It's not something you can just add on the side.
Books? No idea, but looks for stuff that talks about the entire lifecycle, and that comes from real world experience.
Oh, and learn some real crypto, so you can avoid both the snake oil and the irrational paranoia.
The Open Web Application Security Project (OWASP) has a Top 10 list, which lists the most serious web application vulnerabilities, discusses how to protect against them, and provides links to more information (http://www.owasp.org/index.php/Category:OWASP_Top_Ten_Project). This might be a good start.
I learned a decent amount from Essential PHP Security*. It doesn't cover everything, but should cover most of the crazy-stupid errors that crop up in a lot of novice php/mysql stuff. Not that the information isn't out there in plenty of places (just like every other topic humanity has ever thought up), but for twenty bucks it's nice to have a hard copy of the essentials in one place.
*Yes, that's a referral link to amazon. But I'd recommend it either way for people getting started with securing their basic LAMP sites.
How are sites slashdotted when nobody reads TFAs?
http://127.0.0.1/
Enjoy.
Insert
It doesn't matter what you do after the fact to secure your web sites, if your scripting is full of holes, trying to plug them up after the fact isn't going to work. For example, you mention MySQL so I gather your code accesses one or more databases? If so do you know what a SQL injection bug is and have you reviewed your code for them? Nothing you do at the point of deployment is going to help fix a SQL injection bug.
I'm afraid that if you're using MySQL and PHP you've moved from the realm of the very basic to something more advanced. You're no longer just talking about slapping static content on the web. People spend years learning how to do these things really well. You should find yourself a good book and get started. Start with a Google. It costs nothing. If you have friends who do web development with similar tools talk to them and see if they'll help point you in the right direction.
Here are some things to get you started. Note that these are language independent things you should do no matter what dev tools you use. You might want to look at something more targetted for PHP as well.
https://www.securecoding.cert.org/confluence/display/seccode/Top+10+Secure+Coding+Practices
Here's the main site.
https://www.securecoding.cert.org/confluence/display/seccode/CERT+Secure+Coding+Standards
The other way to go would be to make your web files more static. However getting rid of everything dynamic may not be a reasonable option in 2009.
These posts express my own personal views, not those of my employer
Here's a good read with a checklist of things to do to secure your website from page 80
http://www.ipa.go.jp/security/vuln/documents/website_security_en.pdf
It's quite easy to understand and if you follow all the recommendations your website should be more secure than average.
I recommend mod_security and mod_evasive. A reverse proxy would help as well. The DoD and NSA have configuration guides that provide tips on securing Apache (as well as IIS).
Either you spend the time to teach yourself about security.
Or you pay someone to do it for you.
Keep you MySQL only accessible via localhost, put a good password on it's root account, and make separate users for each database with access restricted to each one. I know it's important. Other than that, if you close ports you don't need , keep your software up to date, and write your own PHP I really don't think you have much too worry about.
but you asked about our applications, not your server setup. So my answer presumes that you are in a hosted environment and are trusting to your host to handle that end.
In that case, the biggest exploits that you are probably easily vulnerable to are SQL injection and JavaScript injection. I highly recommend that you research those two things, they will go a long way toward securing your website.
The Kaspersky anti-virus website fell victim to SQL injection just yesterday... but it is an easy thing to prevent with a little knowledge and diligence.
It's possible to write secure code in PHP, but almost nobody does, and most of the PHP code that you can acquire easily is painfully insecure.
Writing secure code with PHP is no more harder than with Perl/Java/Ruby... same rules apply. I would even say nowadays it's extremely easy - use PDO with prepared queries, and you've pretty much eliminated SQL injections. Don't reinvent the wheel - for example Zend Framework is pretty cabable and done most of the work for you which you'd probably end up doing.
In a nutshell:
Validate your goddamned data. Use prepared queries to prevent SQL injections. And so on. The language used itself has very, very little to do with security in the end.
- very very imho -
backups don't help your users who might be attacked by your compromised sites but the ability to wipe the bad and restart is great. requires multiple levels of backups, daily, weekly, monthly, all separate.
You can't restart immediately, presumably you'll get nailed by the same exploit when you recover, but at least you'll know there's a specific problem - finding something specific is nearly always easier than finding something general.
also, control your URLs. controlling what can be passed to your site controls a hell of a lot of security problems.
lastly - make sure your logs are good and safe and verbose. if you pay attention to making the logs right, when you have a problem, you can find someone to review the logs and find the issue. if you don't have the logs, well. you're more screwed.
Do those three things and some common sense when coding and you'll be better off than most. Security is always where you draw the line, personally I like it a bit ahead of the curve but no where near perfect.
closed minded is as closed minded does
There are some good automated security scanners out there. For instance: Nesses/Nikto, WebScarab with proxmon, portswigger, and you can even go as far as using 3rd party companies such as HackerSafe.com or SecurityMetrics.com. Even though this doesn't give you a 100% fail-safe security scenario (*cough* nothing does and probably never will), it at least helps decrease the chances of common and even some more uncommon attacks such as SQL injections, overflows, man-in-the-middle attacks, etc. You also obviously have to write secure code and keep all of your software up to date (especially open source software). This is not only true for PHP, but for all programming languages. You should also try using BSD since you have a LAMP system. Some other good sources of information: http://www.webappsec.org/ http://www.owasp.org/ Hope this helps...
First and foremost, check and sanitize EVERY input passed via a $_POST or $_GET (and to be safe, check cookie inputs too).
Make SURE that none of them are in a format or contain data that you don't expect.
It is easier said than done, and it sucks major ass to do, but it's really the only way to be sure of what you are doing.
I just spent most of the last week tracking down an XSS exploit for a client, and it was a mother to find where to filter the input AND what to look for. SOME inputs needed SOME HTML tags to pass through, others required binary data, and still others needed integers.
My advice on new code is to check your inputs like crazy before assigning any submitted data to a variable. Then check the variables themselves.
Watch for hex encodings of HTML characters, and then watch for it again.
Then, after all that work, hope it works, then drink heavily.
Kaspersky
I just got back from a PHP security class, here's a quick overview of what was covered:
- register_globals = off
- Use the Suhosin PHP hardening patch.
- Always filter all of your input for injection attempts. Write a validation class to handle this.
- Use prepared SQL statements, or stored procedures to help avoid sql injections
There are some pretty good articles out there that cover most of these points and more, just google for "PHP security". Take the time to read the articles, they're worth it.
It's really sad that more people don't pay attention to PHP security. The class I took was, as far as I know, the only commercial PHP security class offered in the US this year, and there were only 4 students in attendance.
exactly right.
Honestly, if the OP is in the situation where he is trying to find and patch holes, it would probably be a better idea to do a little homework and start the project over again and use good security techniques when writing.
It is not that hard, really. You just have to remember never to trust user input. That means that you filter all of it, you don't rely on cookies for access control, and you don't trust the variables that the browser sent you (such as $_SESSION['http_referer']).
As far as filtering is concerned, remember that php has a lot of filters at your disposal (just remember to strip new lines out of email addresses yourself, the filter misses that one). Another word of warning: if you are echoing user input out onto a page, it is much easier to use bb syntax than allow html tags through strip tags: the danger is that an attacker can get javascript attributes the filter and it is better just to avoid it.
weirdest thing I ever saw: scientology advertising on slashdot.
Ensure your users pick good passwords, by preventing them from entering passwords described here (e.g. their firstname, "password", "qwerty", etc).
Slartibartfast:"Is that your robot?"
Marvin:"No, I'm mine."
Agreed with everything you said. You could write your own classes to turn PHP into acting strongly typed, then sanitize your data after it's been type checked, but that might be beyond the scope of this project. Save yourself some hassle and read this too: http://devzone.zend.com/node/view/id/168 It will help validating those inputs.
I'm not suggesting this is rock-solid security. It's a few easy steps that keeps most of the knuckleheads at bay.
Seth
$5 / month hosted VPS on linux = awesome!
You can write insecure websites using pretty much any tools, but if you're using MySQL and PHP, especially if you're using other peoples code in your app, you're probably going to end up with a security nightmare, regardless of how hard you try.
Taken to the extreme you could prepare you own active page servlet using FORTRAN and obfuscate the binaries, randomize query url generation, and run everything on your server through a microkernel operating system where you change all of the system calls and commands to things only you know.
Then operate your website entirely anonymously with tenneling through tor between your actual webserver and the server putting up your domain.
http://www.aaronrogier.net
You can write insecure websites using pretty much any tools, but if you're using MySQL and PHP, especially if you're using other peoples code in your app, you're probably going to end up with a security nightmare, regardless of how hard you try.
That's the problem.
Most of the pros on here can write good-quality, secure code, in PHP, RoR, whatever.
It's the external libraries which are the gap. For example, look at phplist, which is used in many places. Now, every installation of it needs to be upgraded. Now. Right now.
Unless you're a 100% fulltime sysadmin, you haven't got the time to be reading the security lists hourly and upgrading phplist etc when required.
The OP is really asking: how do I make sure phplist and the other hundred Ruby gems or PHP add-ins are up-to-date and safe? And keep them that way?
http://blog.grcm.net/
http://xkcd.com/327/
Apart from speeding the recovery in case of a breaking/defacement it will also assist you if your hosting service goes bust, stops serving or you find someone else who's better / cheaper / has more facilities.
I'm not saying you shouldn't apply sensible security precautions, but don't treat them as if they'll make your sites impregnable. The ability to quickly restore a site means you don't have to go around checking each link on every page to see if it's been messed with.
politicians are like babies' nappies: they should both be changed regularly and for the same reasons
The banks are already broken. Too late.
== Jez ==
Do you miss Firefox? Try Pale Moon.
Buy everyone on /. a pony
I could do with the extra protein.
Finally had enough. Come see us over at https://soylentnews.org/
You can start here:
https://buildsecurityin.us-cert.gov/daisy/bsi/articles/knowledge/principles/358-BSI.html
And for specifically for web apps:
https://buildsecurityin.us-cert.gov/daisy/bsi/articles/best-practices/assembly/639-BSI.html
Then you frighten yourself by playing with the toys here:
http://insecure.org/
Another useful read (albeit not focused on PHP per-se) is David Wheelers Secure Programming (http://www.dwheeler.com/secure-programs/)
I have a simple guide when I write code, it's not flawless but it covers a lot of bases - every time I load a variable that has anything to do with generated content (i.e. from a user) I sanitise it - I don't report errors, I just strip out invalid characters (as a rule). It's not the best way to do it, but combined with a good site design it helps a lot.
Me failed English...
FreeBSD over Linux. If my comments seem odd, this may explain...
"the PCI DSS is a security standard for payment card industries. Their documents go into detail on the specific vulnerabilities that needs to be addressed to be certified. For example they mention specific flaws (say cross-site scripting), and also measures to protect data if an attack succeeds"
.. install a firewall, don't use default passwords, encrypt the transmission data, assign a unique ID to each user, restrict physical access to cardholder data, track all access to network resources and ..
.. :)
All the PCI standard does is set down a number of criteria to be PCI certified. In the real world this provides no defense against getting hacked, as Heartland Payment Systems learned to their regret.
"This document lists specific flaws that are known to be a problem, and had better be comprehensive since these are the standards banks are measured against. "Comprehensive" is perhaps a gross understatement, but it will give you an idea of the aspects to watch out for"
If you need this PCI standard to tell you how to secure your network, then perhaps you shouldn't be in the security industry. Lets see what the 'document' has to teach us that we don't already know:
WOW, I would never have thought of that. But how does one go about getting PCI certified, well there is self assessment or an 'on-site data security assessment' by a suitable qualified security assessor (QSA). How do you get QSA qualified, by filling in a bunch of forms
The problem is that MOST sites that get 0wn3d are running phpbb or other very common and popular packages. They are getting better but they are still the most hacked because it's easy to identify what your site is using and then go and find the exploits for that site.
the SAFEST is typically custom code. and go NUTS on everything that comes from a user treating it like it's a bomb every time. It causes the kiddie to take a LOT of time to crack you, they typically move along for easier fields quite quickly. Back in the early 2000's I used to taunt the "crackers" and "kiddies" if you tried banging on my telnet or ssh door, you were actually banging on my taunt the L0ser door. It would insult the hell out of them and make them think their bot got in because it would give a successful login every time and then taunt the hell out of them and "logoff" I had a single little turd in chicago banging on me for a month until he got his buddies involved and they DDOS attacked my box with all of them trying to attack 120 bored kiddies can bring down a T1 fast, it lasted for 3 days. Funny part was 4 of them was doing it from home and when I personally called their parents all the attacks stopped. (They were on Comcast cable modems and I worked for Comcast at the time so I got the customer contact info quite easily.)
You more than likely do not have the resources I did, so dont provoke them. Taunting the lions is fun, but they now have an army of robots.
Step 1 look through you logs DAILY. 99.999782% of all website admins do not do this. Sorry but you cant spot strange things without going through logs. get a parser that makes it easier, but do it.
Step 2 learn to write secure php code and then write your sites scripts custom. Got a mailer for a contact us page? HARD CODE the to: address and get ready for the never ending fight to filter out spam.
Step 3 Backups.. never TRUST a backup you make from the site, your only real backup is the files you created and uploaded.
Step 4 review everything monthly go over stuff, look for broken or strange, go over all of it.. Look there's a wierd file in your ftp area.. how did that get there?
If you are running phpbb or drupal or other "popular" scripts you needto update them weekly. phpbb has patches all the time and MOST dont get applied by sites that get cracked.
Do not look at laser with remaining good eye.
Or rather, the input your user gives you.
Let's leave aside non-web vulnerabilities for now - of course you'll want to use SFTP and SSH instead of unsecured FTP or Telnet to connect to your server, and HTTPS for your web admin panel, but these are outside the scope of the actual website - they're for your host to deal with.
When you write any kind of dynamic website, user input is the threat. Your website communicates via text with other layers such as the database (SQL) or the users' browser (HTML). Your two biggest risks are SQL injection (where user input breaks out of SQL quotes) and Cross Site Scripting/Request Forgery (where one user's input is executed as Javascript in another user's browser).
Another threat is performing actions (such as deleting/editing content) via GET requests, which will allow search spiders or content prefetchers to wreak havoc.
Comment removed based on user account deletion
0) Use a version control system
1) Validate input, escape output
2) Turn off unused services
3) Regular, automatic backups to another location
Ok, the OWASP list is more comprehensive, but these four things are fundamental to preventing, and recovering from, security breaches.