From the researcher (edik) who discovered the vulnerability:
Using the bulk edit feature you can publish posts and pages PUBLICLY without the publishing-cap. The problem is that there are no checks for publishing-cap's on serverside. It's only protected in UI.
How to reproduce:
1. Login as contributor
2. Create a draft post
3. Mark the draft in post list and open the bulk edit form
4. Make use of tools like Firebug to change a value in the status dropdown. You have to set the value of an entry to 'publish'
5. Select the changed status entry
6. Push the button and welcome to the next level