Addendum: Further in my installation trials I realize that this answer has been incomplete, so I'll edit it. The solution below solves the permission problems with the files in
/static-sympa. But you'll probably run in further problems down the line, because the config snippet in
/etc/apache2/conf.d/sympa is really incomplete. You can replace the whole contents of this file by the version shown at Debian Wiki. There you also find instructions how to create the necessary wrapper at
/var/www/sympa/wwsympa.fcgi. With this, Sympa itself and the web interface WWSympa should be working.
I realize this question is a bit older, but I just run into a similar problem. Maybe the solution I found can help others.
The Sympa package in Ubuntu seems to be a bit bungled, to say the least. One of the problems is that it tells Apache where to find its stuff, but doesn't give it permission to go there ;)
/static-sympa is an Alias that is definied in
/etc/apache2/conf.d/sympa, along with the ScriptAlias for
/wws. The actual location for the files that are aliase'd to
/var/lib/sympa/static_content. That, of course, is miles away from any DocumentRoot Apache knows about. And Apache is wary about integrating stuff from "outside", unless you explicitely tell it it's ok. So the default is, "you no touching anything there", i. e. "403 - Forbidden".
To give Apache the needed permission, you can just extend the configuration snippet,
/etc/apache2/conf.d/sympa. Below the existing Alias and ScriptAlias definition, you can do something along the lines of
# For anything below the (URL) location /sympa-static
Order allow,deny # order of permissions: First handle 'allows', then 'denys'
Allow from All # allow access to anybody