Re: [gentoo-dev] Review: Apache AddHandler news item

[Sebastian Pipping]

On 26.03.2015 18:02, Michael Orlitzky wrote:
> The most important reason is missing =)
>
> If you are relying on the AddHandler behavior to execute
> secret_database_stuff.php.inc, then once the change is made, Apache will
> begin serving up your database credentials in plain text.

Good point.


Changes:

 * Revision bump

 * Add section on .php.inc

 * Add thanks line


================================================================
Title: Apache AddHandler vulnerability protection
Author: Sebastian Pipping <sping@g.o>
Content-Type: text/plain
Posted: 2015-03-26
Revision: 2
News-Item-Format: 1.0
Display-If-Installed: www-servers/apache

Apache's directive AddHandler [1] can be used to map
certain file name extensions (e.g. .php) to a handler
(e.g. application/x-httpd-php).  While a line like

  AddHandler application/x-httpd-php .php .php5 .phtml

matches index.php, it also matches index.php.png.

Apache's notes on multiple file extensions [2] document
a multi-language website as a context where that behavior
may be helpful.  Unfortunately, it can be a security threat.

Combined with (not just PHP) applications that support
file upload, the AddHandler directive can get you into
remote code execution situations.

That is why app-admin/eselect-php now avoids AddHandler
and is shipping

  <FilesMatch "\.(php|php5|phtml)$">
    SetHandler application/x-httpd-php
  </FilesMatch>

instead.


Why this news entry?

 * Since Apache configuration lives below /etc,
   you need to run etc-update (or a substitute)
   to actually have related fixes applied.

 * If you are currently relying on AddHandler to execute
   secret_database_stuff.php.inc, moving away from AddHandler
   could result in serving your database credentials in plain
   text.  A command like

     find /var/www/ -name '*.php.*' \
                 -o -name '*.php5.*' \
                 -o -name '*.phtml.*'

   may help discovering PHP files that would no longer be executed.

 * You may be using AddHandler at other places,
   including off-package files.  Please have a look.

 * app-admin/eselect-php is not the only package
   affected.  There is a dedicated tracker bug at [3].
   As of the momment, affected packages include:

     app-admin/eselect-php[apache2]
     dev-lang/php[apache2]
     net-nds/gosa-core
     www-apache/mod_fastcgi
     www-apache/mod_flvx
     www-apache/mod_python
     www-apache/mod_suphp
     www-apps/moinmoin
     www-apps/rt[-lighttpd]


Thanks to Nico Suhl and Michael Orlitzky.

[1] https://httpd.apache.org/docs/current/mod/mod_mime.html#addhandler
[2] https://httpd.apache.org/docs/current/mod/mod_mime.html#multipleext
[3] https://bugs.gentoo.org/show_bug.cgi?id=544560