The top 10 reasons Web sites get hacked

Web developers ignore security flaws at customers' peril

Web security is at the top of customers' minds after many well-publicized personal data breaches, but the people who actually build Web applications aren't paying much attention to security, experts say.

"They're totally ignoring it," says IT consultant Joel Snyder. "When you go to your Web site design team, what you're looking for is people who are creative and able to build these interesting Web sites... That's No. 1, and No. 9 on the list would be that it's a secure Web site." Read the latest WhitePaper - State of Internet Security Report on Protecting Enterprise Systems

The biggest problem is designers aren't building walls within Web applications to partition and validate data moving between parts of the system, he says.

Security is usually something that's considered after a site is built rather than before it is designed, agrees Khalid Kark, senior analyst at Forrester.

"I'd say the majority of Web sites are hackable," Kark says. "The crux of the problem is security isn't thought of at the time of creating the application."

That's a big problem, and it's one the nonprofit Open Web Application Security Project (OWASP) is trying to solve. An OWASP report called "The Ten Most Critical Web Application Security Vulnerabilities" was issued this year to raise awareness about the biggest security challenges facing Web developers.

The first version of the list was released in 2004, but OWASP Chairman Jeff Williams says Web security has barely improved. New technologies such as AJAX and Rich Internet Applications that make Web sites look better also create more attack surfaces, he says. Convincing businesses their Web sites are insecure is no easy task, though.

"It's frustrating to me, because these flaws are so easy to find and so easy to exploit," says Williams, who is also CEO and co-founder of Aspect Security. "It's like missing a wall on a house."

Here is a summary of OWASP's top 10 Web vulnerabilities, including a description of each problem, real-world examples and how to fix the flaws.

1. Cross site scripting (XSS)

The problem: The "most prevalent and pernicious" Web application security vulnerability, XSS flaws happen when an application sends user data to a Web browser without first validating or encoding the content. This lets hackers execute malicious scripts in a browser, letting them hijack user sessions, deface Web sites, insert hostile content and conduct phishing and malware attacks.

Attacks are usually executed with JavaScript, letting hackers manipulate any aspect of a page. In a worst-case scenario, a hacker could steal information and impersonate a user on a bank's Web site, according to Snyder.

Real-world example: PayPal was targeted last year when attackers redirected PayPal visitors to a page warning users their accounts had been compromised. Victims were redirected to a phishing site and prompted to enter PayPal login information, Social Security numbers and credit card details. PayPal said it closed the vulnerability in June 2006.

How to protect users: Use a whitelist to validate all incoming data, which rejects any data that's not specified on the whitelist as being good. This approach is the opposite of blacklisting, which rejects only inputs known to be bad. Additionally, use appropriate encoding of all output data. "Validation allows the detection of attacks, and encoding prevents any successful script injection from running in the browser," OWASP says.

Join the Good Gear Guide newsletter!

Error: Please check your email address.

Our Back to Business guide highlights the best products for you to boost your productivity at home, on the road, at the office, or in the classroom.

Keep up with the latest tech news, reviews and previews by subscribing to the Good Gear Guide newsletter.

Jon Brodkin

Network World
Show Comments

Essentials

Lexar® JumpDrive® S57 USB 3.0 flash drive

Learn more >

Microsoft L5V-00027 Sculpt Ergonomic Keyboard Desktop

Learn more >

Mobile

Lexar® JumpDrive® S45 USB 3.0 flash drive 

Learn more >

Exec

Lexar® JumpDrive® C20c USB Type-C flash drive 

Learn more >

HD Pan/Tilt Wi-Fi Camera with Night Vision NC450

Learn more >

Audio-Technica ATH-ANC70 Noise Cancelling Headphones

Learn more >

Lexar® Professional 1800x microSDHC™/microSDXC™ UHS-II cards 

Learn more >

Budget

Back To Business Guide

Click for more ›

Most Popular Reviews

Latest News Articles

Resources

PCW Evaluation Team

Azadeh Williams

HP OfficeJet Pro 8730

A smarter way to print for busy small business owners, combining speedy printing with scanning and copying, making it easier to produce high quality documents and images at a touch of a button.

Andrew Grant

HP OfficeJet Pro 8730

I've had a multifunction printer in the office going on 10 years now. It was a neat bit of kit back in the day -- print, copy, scan, fax -- when printing over WiFi felt a bit like magic. It’s seen better days though and an upgrade’s well overdue. This HP OfficeJet Pro 8730 looks like it ticks all the same boxes: print, copy, scan, and fax. (Really? Does anyone fax anything any more? I guess it's good to know the facility’s there, just in case.) Printing over WiFi is more-or- less standard these days.

Ed Dawson

HP OfficeJet Pro 8730

As a freelance writer who is always on the go, I like my technology to be both efficient and effective so I can do my job well. The HP OfficeJet Pro 8730 Inkjet Printer ticks all the boxes in terms of form factor, performance and user interface.

Michael Hargreaves

Windows 10 for Business / Dell XPS 13

I’d happily recommend this touchscreen laptop and Windows 10 as a great way to get serious work done at a desk or on the road.

Aysha Strobbe

Windows 10 / HP Spectre x360

Ultimately, I think the Windows 10 environment is excellent for me as it caters for so many different uses. The inclusion of the Xbox app is also great for when you need some downtime too!

Mark Escubio

Windows 10 / Lenovo Yoga 910

For me, the Xbox Play Anywhere is a great new feature as it allows you to play your current Xbox games with higher resolutions and better graphics without forking out extra cash for another copy. Although available titles are still scarce, but I’m sure it will grow in time.

Featured Content

Latest Jobs

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?