Slashdot Mirror
Cross-Site Scripting Worm Floods MySpace
DJ_Vegas writes "One clever MySpace user looking to expand his buddy list recently figured out how to force others to become his friend, and ended up creating the first self-propagating cross-site scripting (XSS) worm. In less than 24 hours, 'Samy' had amassed over 1 million friends on the popular online community. According to BetaNews, the worm's code utilized XMLHTTPRequest - a JavaScript object used in AJAX Web applications and was spreading at a rate of 1,000 users every few seconds before MySpace shut down its site. Thankfully, the script was written for fun and didn't try to take advantage of unpatched security holes in IE to create a massive MySpace botnet."
Is it really XSS if it's all happening at the same site? Just sayin.....
XMLHTTP has a same-site policy... the problem here is they let users render html & javascript in their own pages on the site. If slashdot allowed executable javascript in the comments, we'd have the same problem.
Is this the first AJAX vulnerability? Something like this would be expected in any new-ish tech that is increasing in popularity.
Myspace was out for a bit? Now you've REALLY given those emo kids something to cry about.
I've got a Myspace page, because it's the most convenient way to keep in touch with some of my old classmates. I've often thought about how few practical applications these kinds of 'social networking' sites provide, aside from general time-wasting. I've also scoffed at the number of young kids who have thousands of friends, as if it's the high school popularity contest in digital form.
./ers have insight as to what kind of malicious applications his XSS could be used for, I welcome the opportunity to learn. Also, what exactly IS XSS? Cross-site (to me) indicates that the script performs a function across multiple webpages... would this refer to all the peers in the Myspace cluster?
So this guy found a way to win the popularity contest. I scoff at him too, though at the same time I must laud him for his creativity. If other
May the threads progress competently.
Go Samy! We're rooting for you over at EFnet #olsentwins!@
If you want to be seen, stand up. If you want to be heard, speak up. If you want to be respected, sit down and shut up.
Here is a recent paper on XSS viruses. Also there is an analysis of the specific MySpace worm.
Evidently LiveJournal and other sites take care to scrub out JavaScript in user-provided web pages, but the rumors are that sometimes people do figure out how to obfuscate their HTML enough to deliver the payload, despite the scrubbers.
And to think that, back in the day, people made friends by actually talking to other people.
He'll probably get a lot of job offers from this.
These '/. is slow and stupid' kind of posts just need to stop. But I listen to 4 different tech podcasts and hadn't heard about this yet. Think about the people who check /. for news while they're at work and most likely away from iTunes and their bookmarks, and (god-forbid) without a readily accessible aggregator. Realize this site for what it is: for the majority of it, other techies posting news they've heard about to a community they might think will care to hear it. This isn't "news as it happens updated every second" so stop treating it like it is.
Perfecting Discordia
www.stevenvansickle.com
In the past, I've been of mixed feelings with IE correctly rendering the "intent" of a web-designer when the web-designer has created buggy HTML - this includes such things as omitting terminating tags (e.g., <l\li>) as well as a few other things. The result of IE doing this was that some web pages look good in IE that didn't look good in other browsers - thus encouraging more people to use IE. As HTML was being used more and more by the masses, there seemed some logic to this. Of course, one of the problems with this idea is that the designers were looking at their web-pages in IE to see if their code was written correctly.
This story just goes to emphasize the importance of calling buggy HTML code what it is, and not trying to infer the intent of the HTML coder. Samy cleverly found a way to make "buggy code" that would get past MySpace's filter, but that would be rendered the way he intended by the browser with the majority market share.
Ben Hocking
Need a professional organizer?
Here is his explanation -- it goes over the transformations he had to make to the program to smuggle it past Myspace's filters.
And here is his version of the story.
He comes off as a sweet practical joker. But maybe that's just b.s. that he cooked up after he realized he might have some 'splainin' to do.
Also, his site really is "namb.la" -- he's making some sort of joke at NAMBDLA's expense, which is pretty suspect, I think.
http://www.thebricktestament.com/the_law/when_to_
... it shouldn't be surprising that someone took it literally and tried to claim it all for himself.
EricWilliam Shatner boldly goes like no man has before
The scoop from himself: http://fast.info/myspace/
This was bound to happen sooner or later, as MySpace repeats the history of the internet. Just look at the huge number of practically unreadable webpages with different size fonts and different colours, terribly innappropriate background images. Oh, and a load of commercial interests trying to stuff things down our throats. Loads of chicks though... ;)
Turns out that he just used the fact that (not trying to start a flame war here) IE and some versions of Safari allow javascript tags within CSS.
Samy's info on the topic (coral)
His explanation of how it works
And the phrase for self-replicating viruses was "gossip". Unfortunately, the viruses would occasionally replicate with mutations, but this only made them stronger.
Ben Hocking
Need a professional organizer?
"Never attribute to malice that which can be adequately explained by stupidity." -- Hanlon's Razor
If /. sucks so much, why are you still here?
Slashdot social media options: AIM, ICQ, Yahoo, Jabber and Mobile Text. Why no MySpace?
Cross-site scripting is a family of vulnerabilities that share these attributes: a) a web-site that takes and displays text (e.g. Slashdot allows you to post comments) and b) a web browser that processes javascript in webpages.
The exploit involves placing javascript code into your posting on a website, such that when other people visit the website their browsers download your comment with the embedded javascript, which is then processed. The javascript, because it is being processed on your machine as part of the rendering of the page, can be used to exploit all sorts of vulnerabilities within browsers. When you have browsers tightly coupled with operating systems, this can open up some rather scary scenarios.
In this case, the guy just used the vulnerability to make some relatively benign changes, but he could have just as easily exploited some of the many problems with IE to be more malicious.
Left shift 1 for e-mail...
All your friends...All your friends...All your friends are belong to us. Its the mega-happy-funtime disco hit of 2005!
They don't have javascript enabled. As far as I can tell, he just used IE's magical ability to run broken code so that the browser would be able to piece together the mess he used, but Myspace wouldnt be able to tell it was javascript.
The Braying and Neighing of Barnyard Animals Follows.
No, actually my pinky finger slipped and hit the "l" instead of the ";". I won't even try to explain how such a slip is possible as my other finger should have been in the way. I think I'm gonna blame quantum tunneling.
Ben Hocking
Need a professional organizer?
That's not the right attitude. The problem lies with web browsers that accept non-standard code.
Malicious code comes in two flavours - code that is outright malicious, and code that is completely benign in browsers that conform to the W3C specifications, but is interpreted wrongly by some browsers to generate a malicious effect.
The first type is easy to filter out, because you can go to the spec and see how things are meant to be interpreted, and from that determine what should be filtered out. The other type, though, is much harder to filter out, as you also need to be aware of all the little quirks and foibles of all browsers likely to be used to access your web application - something that isn't written down anywhere most of the time.
For example, you might have written code that strips out HTML tags. That's fine, except some versions of Netscape Navigator 4.x treat entirely different Unicode characters as if they were < and >. As a web developer, you have no way of knowing about this unless you are privy to some of the most obscure browser trivia in the world, so unless you take a default deny policy and outlaw any non-ASCII characters (goodbye international visitors), you are likely to write code that is vulnerable to this attack - for Netscape 4 users.
Now multiply that problem by all browsers in use today, and all the little quirks and deviations from spec. that they have, and you'll start to get an idea of why it's not feasible for web developers to be responsible for this problem, and why the responsibility lies at the browser developers' feet.
Bogtha Bogtha Bogtha
What would encryping anything have accomplished, exactly? The problem isn't that someone intercepted a legitimate transfer in the middle and modified it to be evil. The problem is that one end of the legitimate transfer was compromised, and the other end of the legitimate transfer was too trusting of the input from the compromised end, and then happily passed along that input (perfectly legitimately) to other parties who were then compromised themselves.
Help poke pirates in the eyepatch, arr.
And because of that, I still use Netscape 3.0 Gold on GUI machines, and I telnet to port 80 on console machines...
;)
Do not look into laser with remaining eye.
while (1) {alert("nope!");} Will DOS any browser in use today. You'll have to kill it via some OS level functionality, because alerts are modal and prevent interaction with the browser chrome. I understand that the JS spec is based on "run to completion", but is there any reason why JS alerts (and confirms, etc) shouldn't be model to the document canvas (disabling interaction with the canvas, but not browser chrome) rather than the browser itself?
I did this. They were more lenient with the javascript back then. You had to use escape characters, but it was no big deal. I wrote a self-propagating worm that changed a user's name to the source of my script. Then I inserted that code into my name. Everyone on myspace had their name changed to 'lupidvirus' after about 6 hours. I got a call from their lawyers the next day at work.
Mine propagated faster than this one because it didn't rely on profile views. Anytime you saw the name, whether it be in a comment, profile, or search, you would be infected. However, with the script executing 100 times per page view, myspace's servers quickly became overloaded and crashed (I didn't really expect it to work). I also essentially staged a DDoS attack against my web server which was hosting the script (it needed to be hosted in order to fit in the 'name' field).
Another note: myspace never removed the scripts that were saved before they outlawed javascript. To this day, I can read a user's inbox and sent messages when they view my profile. I also was going to write a DHTML roleplaying game that ran on myspace, but they locked that account because of the virus. It still plays music and lets you manipulate your inventory though =D
And the phrase for self-replicating viruses was "gossip". Unfortunately, the viruses would occasionally replicate with mutations, but this only made them stronger.
At my school, I think it was called "herpes".
LiveJournal's cleanhtml.pl already covers multiline splits in IE. It's not like IE's interpretation of single tags split on mutiple lines hasn't been known about for quite some time.
I completely agree that IE is the problem, but to say that this is something site administrators couldn't have been prepared for is untrue. To expect a self replicating javascript? No way. But to secure the filter to prevent multiline tags? Yes, cleanhtml.pl already does. It's known and out there already.
From the horses's mouth:
http://namb.la/popular/tech.html