I just upgraded from Ubuntu server to 14.0.4 LTS and I can no longer access Mailman via the Web Interface. I get a 403 forbidden error (Forbidden: You don't have permission to access /cgi-bin/mailman/). I've gone over the apache configuration a few times now and don't see the issue.
I am running Apache 2.4.7 and Mailman 2.1.16. Here is the configuration in my /etc/mailman/apache2.conf. I'm not sure where else to look at this point. Could it be a virtual host issue?
# Logos:
Alias /images/mailman/ /usr/share/images/mailman/
# Use this if you don't want the "cgi-bin" component in your URL:
# In case you want to access mailman through a shorter URL you should enable
# this:
#ScriptAlias /mailman/ /usr/lib/cgi-bin/mailman/
# In this case you need to set the DEFAULT_URL_PATTERN in
# /etc/mailman/mm_cfg.py to http://%s/mailman/ for the cookie
# authentication code to work. Note that you need to change the base
# URL for all the already-created lists as well.
<Directory /usr/lib/cgi-bin/mailman/>
AllowOverride all
Options +ExecCGI
AddHandler cgi-script .cgi index.cgi
Order allow,deny
Allow from all
</Directory>
<Directory /var/lib/mailman/archives/public/>
Options +FollowSymlinks
AllowOverride all
Order allow,deny
Allow from all
</Directory>
<Directory /usr/share/images/mailman/>
AllowOverride all
Order allow,deny
Allow from all
</Directory>