Have you applied all the patches (including the kernel patches)? There isn't one directly connected with CUPS but some ills have been corrected. The kernel patches are only for 64-bit, and all the others do bring the machine up to current stable. Depending upon which browser you're using (Firefox being the recommended one), that may explain or help. There is absolutely no reason that you can't open CUPS with Firefox unless you've fiddled with settings or added additional software.
If you haven't done the patches, you can find them at
http://ftp.osuosl.org/pub/slackware/...ches/packages/ and it would be a good idea to download and apply them all. I use
wget to get the patches and apply them manually because I have more than one machine and it's just easier for me to do that, you can use whatever tool you like.
Have you done a full install of Slackware? Have you added or removed packages (if so, what)? Do you have IPTABLES that may be blocking
localhost? Do you have a router that may not be passing
localhost?
You might try removing and reinstalling CUPS just to see if that helps (it shouldn't but who knows).
It's normal that CUPS works out-of-the-box. Unless something was changed to interfere with that, it ought to just go. CUPS doesn't have a document root as such (it's not in
/var/www/htdocs). All the CUPS software is ower-group root.root. Has that by any chance been altered? For example, look at
Code:
ls -al /usr/bin/*cups*
-r-xr-xr-x 1 root root 11048 Oct 10 2013 /usr/bin/cancel-cups*
-rwxr-xr-x 1 root root 27600 Jul 20 2012 /usr/bin/cups-calibrate*
-r-xr-xr-x 1 root root 3413 Oct 10 2013 /usr/bin/cups-config*
-r-xr-xr-x 1 root root 10968 Oct 10 2013 /usr/bin/cupstestdsc*
-r-xr-xr-x 1 root root 46904 Oct 10 2013 /usr/bin/cupstestppd*
-r-xr-xr-x 1 root root 14112 Oct 10 2013 /usr/bin/lp-cups*
-r-xr-xr-x 1 root root 13840 Oct 10 2013 /usr/bin/lpq-cups*
-r-xr-xr-x 1 root root 11472 Oct 10 2013 /usr/bin/lpr-cups*
-r-xr-xr-x 1 root root 7368 Oct 10 2013 /usr/bin/lprm-cups*
-r-xr-xr-x 1 root root 24176 Oct 10 2013 /usr/bin/lpstat-cups*