A few weeks ago ownCloud 4.0.0 was released and it included some cool features like encryption of uploaded files. I decided to take it for a spin again.

I found again some XSS vulnerabilities. As last time, I reported these issues to the ownCloud team which responded quickly and fixed them already (with version 4.0.2). As far as I can tell CVE-2012-4396 was assigned to these issues (and others were merged into it as well).

/?app=media
1) change ID3 title tag of a MP3 file to: “Kalimba<script>alert(1)</script>”
2) upload
3) play it in the integrated player, JS gets executed

Now this is fun! Imagine someone sending you a MP3 which you listen to with ownCloud and in the background your cookies are sent to a remote system. If you run a ownCloud instance with multiple users, you can also share those files. It might be enough to listen to a shared MP3 to get your account compromised, I didn’t verify this though.

/?app=files&getfile=download.php
1) upload picture e.g. trollface.jpg
2) rename picture to “trollf<style onload=alert(1)>ace.jpg”
3) view the picture, JS gets executed

Can’t think of a good scenario for this to be useful. Maybe sharing this file.

/?app=calendar
1) add new appointment, title: “XSS <script>alert(1);</script>”
2) switch calendar view to “list”, JS gets executed

This was a bit surprising as the normal calendar view was not affected, only the list view.