Apache exec() command

Ra'Jiska · 01-16-2016, 07:10 AM

Hello,

I've been trying to use the exec() command over Apache2 2.4.7 webserver but it did not worked when I was going through the PHP scripts, which is:

PHP Code:



<?php 
exec("wine main.exe"); 
?>

My main.exe file is just for the debug, it is a C++ code that aims to create a file once triggered:

PHP Code:



#include <iostream> 
#include <fstream> 
 
int main (int argc, char *argv[]) 
{ 
    std::ofstream ofile("TMP_FILE"); 
    ofile << "HELLO WORLD !" << std::endl; 
    ofile.close(); 
     
    std::cout << "Done" << std::endl; 
}

However, when I use PHP binary to trigger the script from command line, the main.exe file gets properly executed and creates the debug file.
Therefore, I think it comes from the webserver itself.

Nothing in error logs could be found, here is the "/etc/apache2/apache2.conf" file:

Quote:

# This is the main Apache server configuration file. It contains the
# configuration directives that give the server its instructions.
# See <removed> for detailed information about
# the directives and /usr/share/doc/apache2/README.Debian about Debian specific
# hints.
#
#
# Summary of how the Apache 2 configuration works in Debian:
# The Apache 2 web server configuration in Debian is quite different to
# upstream's suggested way to configure the web server. This is because Debian's
# default Apache2 installation attempts to make adding and removing modules,
# virtual hosts, and extra configuration directives as flexible as possible, in
# order to make automating the changes and administering the server as easy as
# possible.

# It is split into several files forming the configuration hierarchy outlined
# below, all located in the /etc/apache2/ directory:
#
# /etc/apache2/
# |-- apache2.conf
# | `-- ports.conf
# |-- mods-enabled
# | |-- *.load
# | `-- *.conf
# |-- conf-enabled
# | `-- *.conf
# `-- sites-enabled
# `-- *.conf
#
#
# * apache2.conf is the main configuration file (this file). It puts the pieces
# together by including all remaining configuration files when starting up the
# web server.
#
# * ports.conf is always included from the main configuration file. It is
# supposed to determine listening ports for incoming connections which can be
# customized anytime.
#
# * Configuration files in the mods-enabled/, conf-enabled/ and sites-enabled/
# directories contain particular configuration snippets which manage modules,
# global configuration fragments, or virtual host configurations,
# respectively.
#
# They are activated by symlinking available configuration files from their
# respective *-available/ counterparts. These should be managed by using our
# helpers a2enmod/a2dismod, a2ensite/a2dissite and a2enconf/a2disconf. See
# their respective man pages for detailed information.
#
# * The binary is called apache2. Due to the use of environment variables, in
# the default configuration, apache2 needs to be started/stopped with
# /etc/init.d/apache2 or apache2ctl. Calling /usr/bin/apache2 directly will not
# work with the default configuration.

# Global configuration
#

#
# ServerRoot: The top of the directory tree under which the server's
# configuration, error, and log files are kept.
#
# NOTE! If you intend to place this on an NFS (or otherwise network)
# mounted filesystem then please read the Mutex documentation (available
# at <removed>);
# you will save yourself a lot of trouble.
#
# Do NOT add a slash at the end of the directory path.
#
#ServerRoot "/etc/apache2"

#
# The accept serialization lock file MUST BE STORED ON A LOCAL DISK.
#
Mutex file:${APACHE_LOCK_DIR} default

#
# PidFile: The file in which the server should record its process
# identification number when it starts.
# This needs to be set in /etc/apache2/envvars
#
PidFile ${APACHE_PID_FILE}

#
# Timeout: The number of seconds before receives and sends time out.
#
Timeout 300

#
# KeepAlive: Whether or not to allow persistent connections (more than
# one request per connection). Set to "Off" to deactivate.
#
KeepAlive On

#
# MaxKeepAliveRequests: The maximum number of requests to allow
# during a persistent connection. Set to 0 to allow an unlimited amount.
# We recommend you leave this number high, for maximum performance.
#
MaxKeepAliveRequests 100

#
# KeepAliveTimeout: Number of seconds to wait for the next request from the
# same client on the same connection.
#
KeepAliveTimeout 5

# These need to be set in /etc/apache2/envvars
User ${APACHE_RUN_USER}
Group ${APACHE_RUN_GROUP}

#
# HostnameLookups: Log the names of clients or just their IP addresses
# e.g., <removed> (on) or 204.62.129.132 (off).
# The default is off because it'd be overall better for the net if people
# had to knowingly turn this feature on, since enabling it means that
# each client request will result in AT LEAST one lookup request to the
# nameserver.
#
HostnameLookups Off

# ErrorLog: The location of the error log file.
# If you do not specify an ErrorLog directive within a <VirtualHost>
# container, error messages relating to that virtual host will be
# logged here. If you *do* define an error logfile for a <VirtualHost>
# container, that host's errors will be logged there and not here.
#
ErrorLog ${APACHE_LOG_DIR}/error.log

#
# LogLevel: Control the severity of messages logged to the error_log.
# Available values: trace8, ..., trace1, debug, info, notice, warn,
# error, crit, alert, emerg.
# It is also possible to configure the log level for particular modules, e.g.
# "LogLevel info ssl:warn"
#
LogLevel warn

# Include module configuration:
IncludeOptional mods-enabled/*.load
IncludeOptional mods-enabled/*.conf

# Include list of ports to listen on
Include ports.conf

# Sets the default security model of the Apache2 HTTPD server. It does
# not allow access to the root filesystem outside of /usr/share and /var/www.
# The former is used by web applications packaged in Debian,
# the latter may be used for local directories served by the web server. If
# your system is serving content from a sub-directory in /srv you must allow
# access here, or in any related virtual host.
<Directory />
Options FollowSymLinks
AllowOverride None
Require all denied
</Directory>

<Directory /usr/share>
AllowOverride None
Require all granted
</Directory>

<Directory /var/www/>
Options Indexes FollowSymLinks
AllowOverride None
Require all granted
</Directory>

#<Directory /srv/>
# Options Indexes FollowSymLinks
# AllowOverride None
# Require all granted
#</Directory>

# AccessFileName: The name of the file to look for in each directory
# for additional configuration directives. See also the AllowOverride
# directive.
#
AccessFileName .htaccess

#
# The following lines prevent .htaccess and .htpasswd files from being
# viewed by Web clients.
#
<FilesMatch "^\.ht">
Require all denied
</FilesMatch>

#
# The following directives define some format nicknames for use with
# a CustomLog directive.
#
# These deviate from the Common Log Format definitions in that they use %O
# (the actual bytes sent including headers) instead of %b (the size of the
# requested file), because the latter makes it impossible to detect partial
# requests.
#
# Note that the use of %{X-Forwarded-For}i instead of %h is not recommended.
# Use mod_remoteip instead.
#
LogFormat "%v:%p %h %l %u %t "%r" %>s %O "%{Referer}i" "%{User-Agent}i"" vhost_combined
LogFormat "%h %l %u %t "%r" %>s %O "%{Referer}i" "%{User-Agent}i"" combined
LogFormat "%h %l %u %t "%r" %>s %O" common
LogFormat "%{Referer}i -> %U" referer
LogFormat "%{User-agent}i" agent

# Include of directories ignores editors' and dpkg's backup files,
# see README.Debian for details.

# Include generic snippets of statements
IncludeOptional conf-enabled/*.conf

# Include the virtual host configurations:
IncludeOptional sites-enabled/*.conf

# vim: syntax=apache ts=4 sw=4 sts=4 sr noet

### Hide Apache2 Signature ###
ServerSignature Off
ServerTokens Prod

Here is the "/etc/php5/apache2/php.ini" file: http://pastebin.com/ZCy8nXPu

Thank you for your help !

jpollard · 01-16-2016, 07:29 AM

1. Wine is for Windows executables, not Linux.
2. You should use the entire path to the executable
3. Depends on the distribution you are using.

RH/CentOS/SL puts apache into a security compartment, and only executables defined for use within that compartment can be used. In addition, the compartment restricts CGI executables to reside within the directories assigned to that purpose (usually the cgi-bin directory). The purpose is to prevent penetrations of apache from accessing files outside that compartment.

Ra'Jiska · 01-16-2016, 07:36 AM

1. Yup', I know it is, I have compiled the file 'main.exe' on Windows and importated it on Linux.
2. Yes, probably, however, this isn't the cause of the issue, I've been trying both methods, same result.
3. Ubuntu 14.04.03

Will see if I can disable all these securities for testing purpose to make sure it isn't what is causing my issue.

jpollard · 01-16-2016, 09:39 AM

Quote:

Originally Posted by Ra'Jiska

1. Yup', I know it is, I have compiled the file 'main.exe' on Windows and importated it on Linux.

Why? There is a perfectly standard c++ system for Linux, and you avoid the problems of importing any security problems that may exist.

Quote:

2. Yes, probably, however, this isn't the cause of the issue, I've been trying both methods, same result.
3. Ubuntu 14.04.03

Will see if I can disable all these securities for testing purpose to make sure it isn't what is causing my issue.

Well, the configuration file itself limits access:

Code:

...
# Sets the default security model of the Apache2 HTTPD server. It does
# not allow access to the root filesystem outside of /usr/share and /var/www.
...

And "access" would include trying to execute wine or the the program.

Ra'Jiska · 01-16-2016, 11:35 AM

Quote:

Originally Posted by jpollard

Why? There is a perfectly standard c++ system for Linux, and you avoid the problems of importing any security problems that may exist.

Yes, I know. The program I made is only for testing purposes.

Actually, I want to run a server which only has a Windows binary, that's the reason why I compiled it on my own Windows version and importated it here.

Well, the configuration file itself limits access:

Quote:

Originally Posted by jpollard

Code:

...
# Sets the default security model of the Apache2 HTTPD server. It does
# not allow access to the root filesystem outside of /usr/share and /var/www.
...

And "access" would include trying to execute wine or the the program.

Yes but the thing is I've been successfully running it in the past, and still am on other dedicated boxs.
It's just I had to completely reinstall a dedicated box but now face troubles into putting things back, even though I have other servers running it just fine.

Ra'Jiska · 01-24-2016, 09:53 AM

Hello,

I have been able to find the issue.
It comes from the Apache2 mpm_itk module.
Every time it is enabled, it prevents the execution of the file for some reason.

However, I need this module, how would I be able to use it and be able to execute my Windows files ? Thanks.

ondoho · 01-24-2016, 04:21 PM

and what is the purpose of this module?
did you read apache documentation on what you can do with it, change settings etc.?

Ra'Jiska · 01-25-2016, 12:46 AM

This module aims to separate privileges within VirtualHosts.
Different VirtualHosts will run assigned users so one cannot read, write or execute another.

I have been looking over the website of this module, but only found that it may contaon some issues

The thing is I am hosting several websites and I don't know any workaround to make sure people can still edit their files via the FTP, but also the webserver to read and execute those files, but also without having other VirtualHosts' intrusions.

ondoho · 01-25-2016, 12:22 PM

Quote:

Originally Posted by Ra'Jiska

This module aims to separate privileges within VirtualHosts.

makes sense that it prevents wine from executing windows exes.
also makes sense to not disable it.

Quote:

I have been looking over the website of this module, but only found that it may contaon some issues

which website?
i'll grant you that, apache's documentation is really heavy stuff.
but you will have to crunch through it somehow; it must be possible to fine-tune that module.

you could start by showing us the documentation & what you tried already & where you failed.

Ra'Jiska · 01-25-2016, 12:25 PM

Quote:

Originally Posted by ondoho

makes sense that it prevents wine from executing windows exes.
also makes sense to not disable it.

which website?
i'll grant you that, apache's documentation is really heavy stuff.
but you will have to crunch through it somehow; it must be possible to fine-tune that module.

you could start by showing us the documentation & what you tried already & where you failed.

Well, actually in the previous version, Wine files were being executed normally.
In addition, Linux binary files are correctly executed, even with the extension, I think it's more like a bug maybe.

The website I have been looking over is this one: http://mpm-itk.sesse.net/ .
After reading all the commands they do provide, I haven't been able to find anything that would fit the job.

Thnaks for your help !