Installed as CGI binary

Possible attacks

General considerations

[edit]

User Contributed Notes Installed as CGI binary - [23 notes]

down

Anonymous ¶

1 year ago


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

down

martelli at geoserve dot com dot br ¶

8 years ago


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.

down

kstone at trivergent dot net ¶

13 years ago


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.

down

Craig Buchek ¶

5 years ago


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.

down

phpD0TnetATmoritzHYPHONnaumannD0Tcom ¶

7 years ago


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.

down

kschroeder at mirageworks dot com ¶

8 years ago


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.

down

Anonymous ¶

8 years ago


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.

down

phil dot ross at gmail dot com ¶

8 years ago


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.

down

pookey at pookey dot co dot uk ¶

8 years ago


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!

down

michel dot jansens at ulb dot ac dot be ¶

12 years ago


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 :-(

down

-1

Omid ¶

8 years ago


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.

down

geeky at geeky dot de ¶

9 years ago


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)

down

pookey at pookey dot co dot uk ¶

10 years ago


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

down

goran_johansson at yahoo dot com ¶

10 years ago


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

down

matled at gmx dot net ¶

10 years ago


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.

down

ruben at puettmann dot net ¶

10 years ago


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 ....

down

clement dot hermann at free dot fr ¶

10 years ago


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

down

phobo#paradise.net.nz ¶

11 years ago


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.

down

yohgaki at hotmail dot com ¶

12 years ago


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?

down

steeven at kali dot com dot cn ¶

12 years ago


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

down

-1

grange at club-internet dot fr ¶

8 years ago


--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).

down

-1

mail at hotmail dot com ¶

11 years ago


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

down

-1

Anonymous ¶

12 years ago


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).

This mirror generously provided by: Yahoo! Inc.

Installed as CGI binary

Table of Contents