[26247] in bugtraq
PHP Resource Exhaustion Denial of Service
daemon@ATHENA.MIT.EDU (Matthew Murphy)
Mon Jul 22 12:06:27 2002
Message-ID: <000801c23058$442dc220$e62d1c41@kc.rr.com>
From: "Matthew Murphy" <mattmurphy@kc.rr.com>
To: "BugTraq" <bugtraq@securityfocus.com>,
"SecurITeam News" <news@securiteam.com>,
"Full Disclosure" <full-disclosure@lists.netsys.com>
Date: Sat, 20 Jul 2002 20:45:17 -0500
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The PHP interpreter is a heavy-duty CGI EXE (or SAPI module, depending on
configuration) that implements an HTML-embedded script language. A
vulnerability in PHP can be used to cause a denial of service in some cases.
PHP's install process on Apache requires a "/php/" alias to be created, as
it resolves CGI paths to a virtual. (e.g, /php/php.exe not C:\php\php.exe).
To solve the obvious security vulnerability posed by allowing PHP to run
from the web, the development team added a cgi.force_redirect option that is
enabled by default in Apache.
However, regardless of the force_redirect value, it is still possible to
load the binary without a script path:
(e.g, http://localhost/php/php)
A problem exists in PHP; specifically, it does not terminate when given no
command-line arguments. A consistent flow of requests like the above will
exhaust all resources for CGI/ASAPI on the server.
Exploit: http://www.murphy.101main.net/php-apache.c
I tried to make sure this would run on Linux/BSD, but no guarantees...
Compiles cleanly on WinMe with MSVC 6.0.
