netstat -an | grep -i listen

Debian Helper Scripts come in handy,
This package include the famous “service” command to conveniently restart programs.
The service command is something that get pre-installed in Fedora therefore, on a switch to Ubuntu or Debian, these scripts will come in handy to maintain a sense of consistency.
If you are on Ubuntu you can install these with:
mod@mod-laptop:~$ sudo [...]

Advisory:
Mozilla Firefox User Interface Null Pointer Dereference Dispatcher Crash and Remote Denial of Service.
Version Affected:
Mozilla 3.0.3 - 1.9.0 Branch (Specifically for Latest Version)
Release Date:
Disclosed: 28 September 2008
Release Date. 28 September ,2008
Description:
The mozilla firefox is vulnerable to user interface event dispatcher null pointer dereference denial of service attacks. The dispatched event created dynamically leads to firefox [...]