cgi scripts fail to run from userdir with "End of script output before headers" errors
Lonni J Friedman
netllama at gmail.com
Thu Oct 9 08:52:56 PDT 2014
I made the changes that you recommended, restarted apache, but it
didn't help. Still getting the same cryptic error. I've attached
userdir.conf with the changes, in case I somehow screwed it up.
thanks
On Wed, Oct 8, 2014 at 7:21 PM, David A. Bandel <david.bandel at gmail.com> wrote:
> Lonnie,
>
> I see two glaring errors:
> 1. no ScriptAlias directive in the userdir.conf file (see main file for
> use)
> 2. The file set up the userdir area read-only. In the cgi-bin stanza, you
> need:
> Require all granted (in 2.4 the two lines Order Allow Deny and Allow from
> all became the one Require line -- it's also more flexible)
> The stanza for the directory above it has Require method GET POST OPTIONS
> which locks this area and subdirectories down
>
> You might want to remove Indexes from your cgi-bin area. Do you really want
> folks to be able to get a directory listing of the cgi-bin directory? (no,
> you really don't)
>
> With those changes and a reload, it should work.
>
> Before you go production, make sure you remove the cgitb (cgi trace back)
> module. No sense giving the bad guys more ammo.
>
> David-
>
> On Wed, Oct 8, 2014 at 2:11 PM, Lonni J Friedman <netllama at gmail.com> wrote:
>>
>> That's correct, the script works just fine when in /var/www/cgi-bin.
>> mod_cgi is explicitly loaded.
>>
>> I've attached my config files. userdir.conf & 01-cgi.conf are
>> included from httpd.conf.
>>
>> On Wed, Oct 8, 2014 at 12:06 PM, David A. Bandel <david.bandel at gmail.com>
>> wrote:
>> > Lonnie,
>> >
>> > OK, there must be a global configuration that's preventing this script
>> > from
>> > running. Can you post your entire config file? If you don't want to do
>> > that, I can provide an alternate means to pass it to me. Also, you said
>> > these run if you put them in your global cgi-bin directory, just not as
>> > a
>> > user, correct? So mod_cgi is loaded (please confirm).
>> >
>> > David-
>> >
>> > On Wed, Oct 8, 2014 at 12:34 PM, Lonni J Friedman <netllama at gmail.com>
>> > wrote:
>> >>
>> >> I saved the script in /home/netllama/public_html/cgi-bin/m.py, made it
>> >> executable for everyone, and ran it manually:
>> >>
>> >> [netllama at netllama cgi-bin]$ ./m.py
>> >> Content-Type: text/plain;charset=utf-8
>> >>
>> >> Hello World!
>> >>
>> >>
>> >> I then attempted to call it from firefox, and I saw another 500
>> >> Internal Server Error:
>> >> [Wed Oct 08 10:32:06.977104 2014] [cgi:error] [pid 26629] [client
>> >> 127.0.0.1:59320] End of script output before headers: m.py
>> >>
>> >>
>> >> I've already got the SetHandler in the config:
>> >> <Directory /home/*/public_html/cgi-bin>
>> >> AllowOverride Indexes AuthConfig
>> >> Options ExecCGI FollowSymLinks
>> >> SetHandler cgi-script
>> >> AddHandler cgi-script .py
>> >> </Directory>
>> >>
>> >> I'm using apache-2.4.10.
>> >>
>> >>
>> >> On Tue, Oct 7, 2014 at 7:26 PM, David A. Bandel
>> >> <david.bandel at gmail.com>
>> >> wrote:
>> >> > Lonnie,
>> >> >
>> >> > Phew -- yep, this is why I hate this error.
>> >> >
>> >> > Try this:
>> >> > /----start of script----/
>> >> > #!/usr/bin/env python
>> >> > # -*- coding: UTF-8 -*-
>> >> >
>> >> > # enable debugging
>> >> > import cgitb
>> >> > cgitb.enable()
>> >> >
>> >> > print "Content-Type: text/plain;charset=utf-8"
>> >> > print
>> >> >
>> >> > print "Hello World!"
>> >> >
>> >> > ----/end of script/----
>> >> >
>> >> > Your script and this one (call it test.py) should both be executable,
>> >> > owned
>> >> > by the same user, and in the user's cgi-bin directory.
>> >> >
>> >> > Ensure you can run both from the command line, then try to run them
>> >> > in
>> >> > apache by connecting with a browser.
>> >> >
>> >> > If test.py works, but your foo.py script doesn't, the problem is in
>> >> > your
>> >> > foo.py script. Make sure your script is outputting a content-type
>> >> > line
>> >> > (see
>> >> > above).
>> >> >
>> >> > If the test.py does not work, we have a configuration issue.
>> >> >
>> >> > Could also add a "SetHandler: cgi-script" to your cgi-directory
>> >> > stanza.
>> >> >
>> >> > BTW: which version of apache? 2.2 or 2.4 (some declarations changed
>> >> > between
>> >> > these two version numbers)
>> >> >
>> >> >
>> >> > David-
>> >> >
>> >> >
>> >> > On Tue, Oct 7, 2014 at 6:17 PM, Lonni J Friedman <netllama at gmail.com>
>> >> > wrote:
>> >> >>
>> >> >> I definitely have suexec enabled:
>> >> >> [Mon Oct 06 16:09:31.518777 2014] [suexec:notice] [pid 20128]
>> >> >> AH01232:
>> >> >> suEXEC mechanism enabled (wrapper: /usr/sbin/suexec)
>> >> >>
>> >> >> Renaming the suexec binary, and retrying didn't really help:
>> >> >> [Tue Oct 07 16:17:15.854011 2014] [cgi:error] [pid 26631] [client
>> >> >> 127.0.0.1:55657] AH01215: (2)No such file or directory: exec of
>> >> >> '/usr/sbin/suexec' failed
>> >> >> [Tue Oct 07 16:17:15.854671 2014] [cgi:error] [pid 26631] [client
>> >> >> 127.0.0.1:55657] End of script output before headers: foo.py
>> >> >>
>> >> >> I added a handler to the "<Directory /home/*/public_html/cgi-bin>"
>> >> >> section of my apache config, but that didn't have any impact on the
>> >> >> problem.
>> >> >>
>> >> >> Any other suggestions?
>> >> >>
>> >> >>
>> >> >> On Tue, Oct 7, 2014 at 6:28 AM, David A. Bandel
>> >> >> <david.bandel at gmail.com>
>> >> >> wrote:
>> >> >> > Lonnie,
>> >> >> >
>> >> >> > With or without suexec, you will need a handler line:
>> >> >> > AddHandler cgi-script .cgi .py
>> >> >> > (make sure the above line has the pertinent extension, like .py
>> >> >> > and
>> >> >> > your
>> >> >> > python script ends in .py)
>> >> >> >
>> >> >> > If using suexec, you should see a line in your error_log:
>> >> >> > suEXEC mechanism enabled
>> >> >> >
>> >> >> > Your script must be runable by suEXEC user. You might find it
>> >> >> > easier
>> >> >> > to
>> >> >> > disable suexec (unless you need it). Just rename the suexec
>> >> >> > script
>> >> >> > and
>> >> >> > restart apache and test. If you the script works but you need
>> >> >> > suexec
>> >> >> > (because you're going to have lots of users that need to run CGI
>> >> >> > scripts),
>> >> >> > then you'll need to troubleshoot the suexec mess.
>> >> >> >
>> >> >> > David-
>> >> >> >
>> >> >> > On Mon, Oct 6, 2014 at 8:55 PM, Lonni J Friedman
>> >> >> > <netllama at gmail.com>
>> >> >> > wrote:
>> >> >> >>
>> >> >> >> Hi David,
>> >> >> >> I was actually leaning towards some kind of apache configuration
>> >> >> >> issue, but clearly i'm not the expert here, or I would have
>> >> >> >> figured
>> >> >> >> it
>> >> >> >> out myself :)
>> >> >> >>
>> >> >> >> To answer your questions:
>> >> >> >> Its a python script that I'm trying to run.
>> >> >> >> $HOME is on the same partition as / (which is the same partition
>> >> >> >> as
>> >> >> >> the apache $DOCROOT). Its all on a development system, not
>> >> >> >> anything
>> >> >> >> resembling production.
>> >> >> >> The user's UID is greater than 1000.
>> >> >> >> I am using suexec.
>> >> >> >>
>> >> >> >> I'd be happy to answer any other questions.
>> >> >> >>
>> >> >> >> thanks
>> >> >> >>
>> >> >> >>
>> >> >> >> On Mon, Oct 6, 2014 at 6:45 PM, David A. Bandel
>> >> >> >> <david.bandel at gmail.com>
>> >> >> >> wrote:
>> >> >> >> > Lonnie,
>> >> >> >> >
>> >> >> >> > This is one of the most annoying, frustrating errors. All it
>> >> >> >> > says
>> >> >> >> > is
>> >> >> >> > that
>> >> >> >> > the script didn't work. This may be permissions. It may be
>> >> >> >> > your
>> >> >> >> > $HOME
>> >> >> >> > mount is non-executable. Difficult to say. You didn't say
>> >> >> >> > what
>> >> >> >> > kind
>> >> >> >> > of
>> >> >> >> > script it was (Perl, PHP, shell). Is the UID of the user
>> >> >> >> > greater
>> >> >> >> > than
>> >> >> >> > 1000?
>> >> >> >> > Are you using suexec?
>> >> >> >> >
>> >> >> >> > I hate this error. Will be either one of the permissions
>> >> >> >> > issues
>> >> >> >> > above
>> >> >> >> > or
>> >> >> >> > some Apache configuration issue (I'm betting on permissions).
>> >> >> >> >
>> >> >> >> > David-
>> >> >> >> >
>> >> >> >> > On Mon, Oct 6, 2014 at 5:57 PM, Lonni J Friedman
>> >> >> >> > <netllama at gmail.com>
>> >> >> >> > wrote:
>> >> >> >> >>
>> >> >> >> >> Howdy folks,
>> >> >> >> >> Any cgi/apach experts still around? I'm trying to get cgi
>> >> >> >> >> scripts
>> >> >> >> >> working from $USERDIR on a new Fedora system, and they all
>> >> >> >> >> fail
>> >> >> >> >> with
>> >> >> >> >> internal server errors. In the apache error log, I see:
>> >> >> >> >> [cgi:error] End of script output before headers
>> >> >> >> >>
>> >> >> >> >> If I copy the script over to the server $DOCROOT/cgi-bin then
>> >> >> >> >> it
>> >> >> >> >> runs
>> >> >> >> >> just fine. So this proves the script itself isn't the
>> >> >> >> >> problem.
>> >> >> >> >> Additionally, non-cgi scripts are served just fine from
>> >> >> >> >> $USERDIR.
>> >> >> >> >> Both the cgi-bin directory and the script itself are
>> >> >> >> >> executable
>> >> >> >> >> for
>> >> >> >> >> all users (755). This is what I've got set in the apache
>> >> >> >> >> config
>> >> >> >> >> for
>> >> >> >> >> the USERDIR directory structure:
>> >> >> >> >>
>> >> >> >> >> <Directory "/home/*/public_html">
>> >> >> >> >> AllowOverride FileInfo AuthConfig Limit Indexes
>> >> >> >> >> Options MultiViews Indexes SymLinksIfOwnerMatch ExecCGI
>> >> >> >> >> Require method GET POST OPTIONS
>> >> >> >> >> </Directory>
>> >> >> >> >>
>> >> >> >> >> <Directory /home/*/public_html/cgi-bin>
>> >> >> >> >> AllowOverride Indexes AuthConfig
>> >> >> >> >> Options ExecCGI
>> >> >> >> >> SetHandler cgi-script
>> >> >> >> >> </Directory>
>> >> >> >> >>
>> >> >> >> >>
>> >> >> >> >> Anyone know what I'm missing?
>> >> >> >> >>
>> >> >> >> >> thanks
>> >> >> >>
--
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
L. Friedman netllama at gmail.com
LlamaLand http://netllama.linux-sxs.org
-------------- next part --------------
#
# UserDir: The name of the directory that is appended onto a user's home
# directory if a ~user request is received.
#
# The path to the end user account 'public_html' directory must be
# accessible to the webserver userid. This usually means that ~userid
# must have permissions of 711, ~userid/public_html must have permissions
# of 755, and documents contained therein must be world-readable.
# Otherwise, the client will only receive a "403 Forbidden" message.
#
<IfModule mod_userdir.c>
#
# UserDir is disabled by default since it can confirm the presence
# of a username on the system (depending on home directory
# permissions).
#
#UserDir disabled
#
# To enable requests to /~user/ to serve the user's public_html
# directory, remove the "UserDir disabled" line above, and uncomment
# the following line instead:
#
UserDir public_html
ScriptAlias /cgi-bin/ "/home/*/public_html/cgi-bin/"
</IfModule>
#
# Control access to UserDir directories. The following is an example
# for a site where these directories are restricted to read-only.
#
<Directory "/home/*/public_html">
AllowOverride FileInfo AuthConfig Limit Indexes
Options MultiViews Indexes SymLinksIfOwnerMatch ExecCGI
# Require method GET POST OPTIONS
# Options MultiViews Indexes SymLinksIfOwnerMatch IncludesNoExec
# AllowOverride AuthConfig Limit FileInfo
</Directory>
<Directory /home/*/public_html/cgi-bin>
Require all granted
AllowOverride AuthConfig
Options ExecCGI FollowSymLinks
SetHandler cgi-script
AddHandler cgi-script .py
</Directory>
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