Top 10 Vulnerabilities in Web Applications

sverrehu writes "The Open Web Application Security Project (OWASP) has released a well-written document that is a must read for every web programmer out there. This security document is not about firewalls, encryption and patching. It's about common, highly exploitable errors made by the application programmers. Pick up your copy of "The Ten Most Critical Web Application Security Vulnerabilities" from the OWASP web site."

Comments

Open Source Needs People to Reuse code

[Anonymous Coward]

One thing I notice is the large numbers of people who keep making the same require() or include() mistakes in php which allow attackers to run remote code. If you look at the relevant full disclosure lists there are several of these posted every week - Scanning tools like the Qualys Scanner spend a large amount of time looking for these easily preventable bugs - there must be thousands of these.

Make open source more secure, share your experience, police each other, make M$ security look bad. When you make a security fix in code make sure you comment it - someone is probably going to copy it as an example. Don't let mistakes or inexperience spread.

Summary

[robbyjo]

1. Unvalidated Parameters
2. Broken access control
3. Broken account and access management
4. Cross-site scripting (XSS) flaws
5. Buffer overflows
6. Command injection flaws
7. Error Handling problems
8. Insecure use of cryptography
9. Remote administration flaws
10. Web and application misconfiguration

Re:Summary

[bwalling]

Err, #1, #5, and #6 can be summarized as: Don't trust user input.

quick reminder..

[Anonymous Coward]

..to those who didnt bother to read the article, it has these lines in it:

This security document is not about firewalls, encryption and patching. It's about common, highly exploitable errors made by the application programmers.

which means every post thats about IIS, Micro$oft, m$, microshaft and god knows what other words you use to make you look like an idiotic open source fanatic with no sense of reality are offtopic.

Relevant to everything:

[White Shade]

"The underlying reality is shameful: most system and Web application software is written oblivious to security principles, software engineering, operational implications, and indeed common sense."

I think a lack of common sense is a problem which applies to almost everything. Judges, certain chip-manufacturing companies, certain companies preventing sales of their better (*cough*alpha*cough*) products, etc, all seem to suffer from this affliction.

Another facet which the article may have neglected to mention is programmers who feel that they're better than the rest of their fellow programmers and so as a result they 'assume' that their software is inherently bug free, because obviously they could never write a buggy applcation.

In the recent case of HP and the Alpha, it seems as though both conceit ('our new chips are better', while quietly ignoring the facts) and a lack of common sense ('hey, how bout we not sell our better and more lucrative product, cuz thatll be fun!') and a dose of good ol' fashioned stupidity are involved...

Lack of common sense, conceit, and stupidity.. While the specifics of this article are clearly about web design, the overall lessons to be learned can, and should, be applied to technology, and life in general.

It's about time common sense became a bit more deserving of the title, and maybe once that happens we won't have to read articles like this one.

a "a must read"?

[farnsworth]

This is far from a "must read", it's good introduction to common mistakes junior developers/admins make with webapps. There's nothing in there that hasn't been covered before or is well-known to anyone who has even the least bit of real-world experience.

It seems like good information and it's well-written, but it's hardly anything ground breaking.

Re:a "a must read"?

[sverrehu]

My experience is different than yours. I've spent the two last years giving courses and lectures on exactly these topics to approximately 700 programmers in everything from small, 10-person companies, via banks, to large, international consulting companies. Far less then half of these experienced developers knew about SQL Injection. Next to none fully understood Cross-site-Scripting-based session hijacking.

I used to spend some late evenings looking for symptomes of SQL Injection and Cross-site Scripting (two of the vulnerabilities most easily detected from the outside without doing something really intrusive). I have a list of 170 sites, including banks and web shops that have symptoms on these problems. That's about half of the sites I've checked.

I've skimmed book upon book on "building E-commerce solutions", and every single one of them contains examples with unintended security holes in them. Even books on web application security contains examples that are vulnerable.

So, I strongly disagree with you. In my experience, most web application programmers know next to nothing about these problems.

READ THE PDF!

[Wakkow]

Don't just scan the summary.. There's nothing that special about the top 10. Read the PDF which actually explains each item, giving examples and what to do about it. That is what makes the site worth looking at.

Well known, but not easy to do . . . .

[djembe2k]

Yes, all of these vulnerabilities are well known, but the reason that they are common mistakes is because it is so much easier to make them than to avoid them. Making people aware of them isn't the same as instructing people in how to avoid them.

While the list is (appropriately) in OS-neutral and scripting language-neutral terms, the way to correct these problems is specific to the OS, webserver and scripting langauge you are using. So the next question is: what are the resources for addressing these issues, specifically, for particular OSes, webservers and languages?

For those taking the MS approach (and flame it if you want, but IIS isn't about to stop being the #2 web server overnight, so it might as well be done as securely as possible), I can recommend the following two guides from SANS:

Securing Internet Information Server

and

Windows 2000/XP Scripting For Security

These are listed as "course books" on their site, but they stand alone as guides for those who already have some background and knowledge. And if you don't have much background and knowledge, SANS courses are very good. (In fact, just about everything at the SANS website is valuable for the IT professional who wants to know more about security -- which ought to be all of us.)

So, stop just posting that these 10 problems are old news, and post the resources you use (or learned from) to avoid these problems yourself on your platform of choice, so the many (majority?) still making these mistakes can learn to avoid them too.

Re:Here's an Example

[GigsVT]

WHERE messageID = form.messageID AND userID = cookie.userID

Yeah, it's a good thing users can't edit the cookies that are stored on their hard disk..... oh wait.

To do something like this securely, give the user a unique session ID and put only that in the cookie. Then manage all their session data on the server side. That's what PHP does.