NetRyder
Tech Junkie
- Joined
- 19 Apr 2002
- Messages
- 13,256
If you're using the Greasemonkey extension for Firefox, you should remove it until an updated version has been released. Bear in mind that this flaw affects all Firefox users who use the Greasemonkey extension, regardless of what OS they're using.
Hat tip to Marc OrchantA serious… no, make that critical flaw has been discovered in Greasemonkey that allows an attacker unfettered access to your system. From the Mozilla discussion thread:
“But wait, it gets worse. An attacker doesn’t even need to know the exact filename, since “GET”ting a URL like “file:///c:/” will return a parseable directory listing. (And Mac users don’t get to gloat either; you’re just as vulnerable, starting with a different root URL.) In other words, running a Greasemonkey script on a site can expose the contents of every file on your local hard drive to that site.
Running a Greasemonkey script with ”@include *” (which, BTW, is the default if no parameter is specified) can expose the contents of every file on your local hard drive to every site you visit. And, because GM_xmlhttpRequest can use POST as well as GET, an attacker can quietly send this information anywhere in the world.”