Archive for April, 2008
Monday, April 21st, 2008
Before going talking about an interesting set of CSRF vulnerabilities that were released this weekend, I did want to take a few moments to do some “housekeeping” on the recent spreadsheets.google.com XSS. (1) I gave the Google Security Team the details for this particular issue well before talking about it on my blog. (2) The described issue was fixed by the GST before I even considered publically speaking about the vuln. (3) Part of the vulnerability involved a caching flaw in Google’s servers, this issue is specific to Google and it was also fixed… OK, on to the good stuff…
A few weeks ago, Rob Carter told me about a few interesting CSRF vulnerabilities that he discovered in a uTorrent plugin (he publicly disclosed them this weekend). Rob was able to chain together the CSRF vulnerabilities and the net result is complete compromise of the victim’s machine! I think this may be the first PURE CSRF vulnerability that I’ve seen that resulted in compromise of a victims machine (there is an argument amongst some of my colleagues as to whether protocol handling/URI vulnerabilities are actually a form of CSRF, but that’s another story). The series of vulnerabilities basically follow this flow:
When a user installs the uTorrent Web UI plugin. the plugin essentially starts a locally running web server on your machine (in order to serve the Web UI). Rob targets the CSRF vulnerabilities associated with this locally running web server.
- Rob uses a first CSRF to turn on the “Move completed downloads” option on the uTorrent Web UI. The CSRF looks something like this:
- Once Rob has “turned on” the “Move completed downloads” functionality, he uses a second CSRF to change the path of where the completed torrent download is placed. In the example he gives, he forces the uTorrent plugin to move completed torrent downloads to the Windows startup folder. This CSRF looks something like this:
- The last step in Rob’s example forces the victim to download a torrent which points to an attacker controlled bat file. Once the file is downloaded, uTorrent places the files into the victim’s startup folder (thanks to the first two CSRFs). This CSRF looks something like this:
Once the file is placed, the next time the user restarts their machine, the attacker controlled file will be run… there you have it… compromise of a victim’s system through three CSRFs! Scary stuff… you can read more about the issue on Robs Blog <robs blog>.
Monday, April 21st, 2008
ToorCon this weekend totally ROCKED. Any venue that has flaming tetherball, major websites getting pwnd, hawt hacker chics pwning backbone protocols, java 0-days, and free beer has to ROCK. All the talks I caught were awesome and the con has inspired me to look into some new avenues of research (aka pwnage).
Thanks to H1kari, tim, Geo, and Phil for having me out!
Tuesday, April 15th, 2008
If you haven’t heard yet, Mark Dowd chopped up a Flash vulnerability ninja style and released a 25 page whitepaper describing his attack. It’s truly a work of art and can be found here. <pdf>
I’m not even going to attempt to describe any portion of this attack (just thinking about it makes my head hurt), but Thomas Ptacek from Matasano has a great writeup <writeup>