The Server Pages
:: TSP Menu
- Home
- Authors
- Glossary
- RSS Feed

:: Servers
- CPanel
- Hosting
- Linux
- Windows

:: Webmaster
- Databases
- Design
- PHP
- Search Engines

:: Scripts
- Scripts

:: Documentation
- PHP Manual

:: Other
- Errors & Solutions
- TechPunt
- Wojjie

search for in the

Possible attacks> <General considerations
[edit] Last updated: Sat, 12 May 2012

view this page in



Possible attacks> <General considerations
[edit] Last updated: Sat, 12 May 2012
 
add a note add a note User Contributed Notes Installed as CGI binary
Anonymous 03-May-2012 04:06
IMPORTANT INFORMATION

There was a serious vulnerability in certain CGI-based PHP setups that has gone unnoticed for at least 8 years.

For PHP this means that a request containing ?-s may dump the PHP source code for the page.

Make sure to update to current versions and/or use an .htaccess patch, both available here:

PHP 5.3.12 and PHP 5.4.2 Released:
http://www.php.net/archive/2012.php#id2012-05-03-1
Craig Buchek 12-Aug-2007 04:33
NOTE: Running PHP as a CGI program will change the value of $_SERVER['SCRIPT_NAME']. When running via the (normal) mod_PHP mechanism, it will be set to the name of (actually, path to) the PHP script that's running. When running via CGI, it will instead point to the path of the CGI binary.
phpD0TnetATmoritzHYPHONnaumannD0Tcom 09-Jan-2006 03:56
One of the most common reasons why you get 'No input file specified' (AKA 'the second most useful error message in the world') is that you have set 'doc_root' (in php.ini) to a value which is to the 'DocumentRoot' defined in the apache configuration.

This is the same for other webservers. For example, on lighttpd, make sure the 'server.document-root' value is the same as what is defined as 'doc_root' in php.ini.
phil dot ross at gmail dot com 22-Mar-2005 09:56
In response to grange at club-internet dot fr:

There are a couple of errors in the mod_rewrite directives given. I found that the following works:

RewriteEngine on
RewriteCond %{ENV:REDIRECT_STATUS} !200
RewriteRule ^cgi-bin/php.cgi - [F]

I removed the = from the RewriteCond and took out the leading / from the RewriteRule.
kschroeder at mirageworks dot com 11-Feb-2005 01:23
I have noticed that some people have noted that running PHP as a CGI program can run slowly compared with a compiled in module.  Some have noted that they want to use FastCGI but are hesitant.  I found that using the Apache 2's CGID module was a great way to speed up performance almost to the same level as an "so"-installed PHP module but you get the added benefit of running each virtual host under it's own user and group. 

In my testing I got 44 pages per second using PHP as a module and I got roughly the same performance (within 5%) running PHP as a CGI program through CGID.

CGID is also really easy to set up.  Just add --enable-cgid to your Apache configure command and you're good to go.  Just set up PHP as a CGI normally.

I'm sure that there's extra RAM used for this method but RAM is as cheap as borscht anyways so it shouldn't be a major factor when trying to speed up PHP CGI.
Omid 04-Jan-2005 04:39
Here are my two cents of knowledge about php-cgi when running CGI script from prompt:

If you get the "No input file specified." error, create the environment variable "SCRIPT_FILENAME=C:\files\test.php".

If you get "Security Alert!" error and it tells you to create the REDIRECT_STATUS environment variable, it is because you have the SERVER_NAME variable set but not the REDIRECT_STATUS variable.

Hence, if you have SERVER_NAME, you also need REDIRECT_STATUS, but not otherwise.

And you pretty much should have SCRIPT_FILENAME at all time.
grange at club-internet dot fr 28-Dec-2004 07:40
--enable-force-cgi-redirect won't work in FastCGI mode : as of 4.3.10, it is only supported in CGI mode.

However, you can achieve the same result with mod_rewrite under Apache :

RewriteEngine on
RewriteCond %{ENV:REDIRECT_STATUS} !=200
RewriteRule /cgi-bin/path/to/php - [F]

This will only allow internal redirection, thus forbidding direct HTTP access to php interpreter (http://www.exemple.com/cgi-bin/path/to/php).
pookey at pookey dot co dot uk 07-Sep-2004 02:58
I've updated my site now to include information about running PHP in CGI mode using BinFMT to remove the need for a shebang, http://www.pookey.co.uk/php-security.xml . Also, http://www.pookey.co.uk/php-suphp.xml documents a few things about suPHP, and http://www.pookey.co.uk/php-suphp-modphp.xml shows a method of runing SuPHP and mod_php together (not covered on suPHP's site).  Hope this is of help to you!
martelli at geoserve dot com dot br 11-Jul-2004 07:25
PHP CGI with VirtualHosts.

This is what I found out while trying to get php to work as CGI with Apache VirtualHosts.

By enabling 'force-cgiredirects', you *must*:
1) set 'cgi.fix_pathinfo=1' in php.ini
2) leave doc_root commented out (php.ini also)

If you miss item 1, the apache logs will show 'unexpected T_STRING' in the php binary.
If you miss item 2, you'll only see 'No input file specified.', instead of the expected output.

You can then turn on the php support for a particular vhost by defining:

Action php-script /cgi-bin/php

inside the corresponding <VirtualHost> directive.
13-Jun-2004 03:26
PHP works with Apache and suEXEC like this:
(Assuming that suEXEC ist allready installed and working)

Install PHP as CGI binary (e.g. in /usr/local/bin/php)
(compile with --enable-force-cgi-redirect)

Create a Link inside cgi-bin directory to make php-cgi accessable:
cd /usr/local/apache/cgi-bin
ln /usr/local/bin/php php

Edit your httpd.conf file:
 AddHandler php4-script .php
 Action php4-script /cgi-bin/php

 <VirtualHost 123.456.789.0:80>
    User exampleuser
    Group examplegroup
     ...
  
 </VirtualHost>

Restart Apache

PHP-scripts are now called under the user-id of exampleuser and group-id of examplegroup.
geeky at geeky dot de 02-Sep-2003 02:32
a replacement for suexec is suphp (http://www.suphp.org).

"suPHP is a tool for executing PHP scripts with the permissions of their owners. It consists of an Apache module (mod_suphp) and a setuid root binary (suphp) that is called by the Apache module to change the uid of the process executing the PHP interpreter." (from the website)
pookey at pookey dot co dot uk 21-Mar-2003 04:29
I have setup a guide to installing PHP with SuEXEC in such a way that shebangs (!#/usr/bin/php4) are not needed.  Hope this is of some help to you.

http://www.pookey.co.uk/php-security.xml
goran_johansson at yahoo dot com 17-Feb-2003 12:53
A tip for Windows-users

Just a tip for you so do not do the same mistake as I did:
I just found out that PHP first seem to look in the php-directory for php.ini, and if that file does not exist, it looks in the Windows directory.
I renamed the file php.ini-dist to php.ini and copied it to my Windows directory, and then I modified the infamous "cgi.force_redirect = 0" in the php.ini file located in the Windows directory, to make it work. But it did not because it reads from the "original" php.ini - So when I deleted this php.ini things started working again
matled at gmx dot net 28-Sep-2002 10:53
If you are using php per cgi and have additionally mod_gzip enabled you have to disable mod_gzip for the php cgi binary to use --enable-cgi-redirect. mod_gzip sets the REDIRECT_STATUS always to 200 which makes it impossible for the php binary to know when it was called directly or when it was called by a redirect.
ruben at puettmann dot net 20-Sep-2002 01:29
To use php-cgi with suexec it will be nice that each virtual host has ist's own php.ini. This goes with :

SetEnv PHPRC /var/www/server/www.test.com/conf

But suexec will kill this enviromet cause It don't know that it is "save" so you must edit the suexec.c for compiling ....
clement dot hermann at free dot fr 18-Jun-2002 04:05
When using php in cgi mode, it's often a good idea to take a look at the apache suexec feature in addition to the --force-cgi-redirect option.

 http://httpd.apache.org/docs/suexec.html
phobo#paradise.net.nz 02-Oct-2001 02:28
If you do virutal hosting, you can turn safe mode on and off for different Apache Virutal Hosts using the php_admin_value directive. This also allows you to have customised maximum execution times, disabled functions, etc; anything which is set in php.ini. Note that by placing a base_dir for each virutal host, this means PHP CANNOT access files below this heirachy; strongly recomended for customer hosting.

Example (httpd.conf):

[VirtualHost 127.0.0.1:80]
 DocumentRoot /var/www/html/safephphost/
 ServerName safephp
 php_admin_value safe_mode 1
 php_admin_value open_base_dir /var/www/html/safephphost/
 php_admin_value sendmail_from phobo#paradise.net.nz
[/VirtualHost]


Am not sure which versions this started working with but does with Apache 1.3.19/PHP4.04pl1.
mail at hotmail dot com 10-Jul-2001 05:14
You can find more security information, about secury programming and how to avoid some common mistakes programming php applications:
http://www.securereality.com.au/studyinscarlet.txt
yohgaki at hotmail dot com 12-Apr-2001 06:44
If you care about security, you are better of setting

register_globals = off
enable_track_vars = on (Always on from PHP4.0.3)

Default setting for variable order is
EGPCS
(ENV VARS/GET VARS/POST VARS/COOKIE VARS/SESSION VARS)

Imagine if you are rely on ENV VAR but it was orver written with GET/POST/COOKIE vars?
michel dot jansens at ulb dot ac dot be 09-Apr-2001 05:21
If you want to use suexec and reference your php interpreter via #!/usr/local/bin/php,  be shure to compile php WITHOUT  --enable-force-cgi-redirect.

This might seems obvious, but I spent 2 days on this :-(
12-Mar-2001 07:39
The configuration option '--enable-force-cgi-redirect' is supported by Zeus Web Server 3.3.8.2 (at least, that's what I've tried it on - it make work on previous versions).
steeven at kali dot com dot cn 18-Jan-2001 07:54
suEXEC require CGI mode, and slow down the scripts. I did them like this:
1. Install php as DSO mode. (for max speed and low secure)
2. Make a seperate CGI install with --enable-force-cgi-redirect, place php to cgi-bin
3 For more secure with suEXEC, choose one of the following method:
3-1: Place a .htaccess file containing this to override main config:
AddType application/x-httpd-wphp php
Action application/x-httpd-wphp /cgi-bin/php
  All php files in subdirectory will be protected.
3-2: add following in httpd.conf:
AddType application/x-httpd-wphp sphp
Action application/x-httpd-wphp /cgi-bin/php
  then each sensitive php file should be renamed to .sphp

Add "php_value doc_root /home/user/html_docs" to each virtual host directive in httpd.conf
kstone at trivergent dot net 03-May-2000 09:01
Better yet, use binfmt_misc:  (linux only)

echo :php3:E::php3::/usr/bin/php: > /proc/sys/fs/binfmt_misc/register

Eliminates the need for the #! at the top of the file.

 
show source | credits | sitemap | contact | advertising | mirror sites