Comment 5 for bug 1130857

David, here's the rather poor workaround I used:

apt-get remove firefox
cd /var/cache/apt/archives
dpkg -i *firefox*18.02*

Then pin Firefox at this version by pasting the following into /etc/apt/preferences.d/firefox:

Package: *firefox*
Pin: version n=18.0.2
Pin-Priority: 999

apt-get update and you should be sorted until this bug is fixed - modulo security holes.