Eu começaria verificando se você tem as últimas Atualização para o BlackSheep de novembro 8.
No artigo Firesheep , iancharnas comenta:
For people receiving the --fix-permissions error, here's what to do:
- Under Applications -> Utilities open Terminal
Copy-and-Paste this command into Terminal and hit [enter]
sudo ~/Library/Application\ Support/Firefox/Profiles/*/extensions/firesheep\@codebutler.com/platform/Darwin_x86-gcc3/firesheep-backend --fix-permissions
It will ask you for your password, type it in.
- Restart firefox and the error should go away.
If you still get the "--fix-permissions" error, you probably have FireVault installed and need to do the following. If you have FileVault enabled, it will mount your home directory as "nosuid", so the packet-capturing backend won't be able to run until you Copy-and-Paste these additional commands into the Terminal to move the firesheep-backend to a place it can run SUID root:
sudo mv ~/Library/Application\ Support/Firefox/Profiles/*/extensions/firesheep\@codebutler.com/platform/Darwin_x86-gcc3/firesheep-backend /usr/bin/firesheep-backend sudo ln -s /usr/bin/firesheep-backend ~/Library/Application\Support/Firefox/Profiles/*/extensions/firesheep\@codebutler.com/platform/Darwin_x86-gcc3/firesheep-backend