Slashdot Mirror
Cross-Site Scripting Hits Major Sites
An anonymous reader writes "Dark Reading and SC Magazine covered a story about hackers posting cross-site scripting (XSS) vulnerabilies en mass on dozens of high profile websites including Dell, MSN, HP, Apple, Myspace, YouTube, MSN, Cingular, etc. The media coverage drew the hacker's attention to the publication's websites where they got a taste first-hand. On message board wall-of-shame is PC World, MacWorld, Fox News, the Independent, and ZDNet UK. "...not only did we get the "scoop" on the XSS site problems, but we also got the message loud and clear: Don't assume you're immune to XSS vulnerabilities. They're everywhere." The news comes shortly after Mitre (CVE) released statistics showing XSS has become the most popular exploit. Unfortunately new XSS attacks are growing increasingly severe and scanners are unable to find many of the issues on modern websites."
I particularly like this example.
Here's the spoiler.
A while ago, someone posted a link to a webpage that, when clicked, caused their post to be moderated up. Their post was at +5 for quite a while until enough replies got moderated up pointing out that the link wasn't what it claimed to be.
So, in a sense, Slashdot has already been hit by a cross-site scripting vulnerability. The fix for XSS vulnerabilities like that involves requiring a secret token to be sent to take user actions, to prevent people from creating forms off-site and submitting them as the user. I suppose checking the referrer may work too, but I wouldn't count on it.
You are in a maze of twisty little relative jumps, all alike.
As a content manager for the U of Rochester when I was a student there, I witnessed thousands of attempts at XSS every month. All of this thanks to one idiot who decided he wanted to put a mambo website up on the student activities server, we had our main server breached and multiple websites defaced. once you're breached, everyone wants to try to hack you again. One interesting thing I noticed is that the majority of XSS attempts will try to call a script in a file with a .gif or .jpg name. This way, if a curious person sees the attempt and tries to visit the linked script, all they get is a broken image. However, the file_get_contents php function, or other such functions, will read those as PHP. I've seen these scripts uploaded to government websites, university servers and many other places. The one that was put on the U of Rochester server attempted to delete all of the files on the server and put in code for what looked like a perl proxy server (i dunno, it was kinda obfuscated, and I'm not too good at perl yet).
The XSS scripts are quite complex, too. Some of them create HTML/javascript console interfaces for people to interact with the server as if they had an SSH connection.
And they're all over the place. I've got a website that's had less than 1000 hits, and I've seen three separate attempts to use XSS on it.