17th Feb 2003 [SBWID-5998]
COMMAND
PHP CGI priviledge escalation and remote file compromise
SYSTEMS AFFECTED
PHP/CGI version 4.3.0
PROBLEM
Thank Kosmas Skiadopoulos for discovering this vulnerability, posted by
The PHP Group :
PHP contains code for preventing direct access to the CGI binary with
configure option "--enable-force-cgi-redirect" and php.ini option
"cgi.force_redirect". In PHP 4.3.0 there is a bug which renders these
options useless.
NOTE: This bug does NOT affect any of the other SAPI modules.
(such as the Apache or ISAPI modules, etc.)
Impact
======
Anyone with access to websites hosted on a web server which employs the
CGI module may exploit this vulnerability to gain access to any file
readable by the user under which the webserver runs.
A remote attacker could also trick PHP into executing arbitrary PHP
code if attacker is able to inject the code into files accessible by
the CGI. This could be for example the web server access-logs.
SOLUTION
The PHP Group has released a new PHP version, 4.3.1, which incorporates
a fix for the vulnerability. All users of affected PHP versions are
encouraged to upgrade to this latest version. The downloads web site at
http://www.php.net/downloads.php
has the new 4.3.1 source tarballs, Windows binaries and source patch
from 4.3.0 available for download. You will only need to upgrade if
you're using the CGI module of PHP 4.3.0. There are no other bugfixes
contained in this release.