Re: Vulnerabilities digest

["Steven M. Christey" <coley@xxxxxxxxxxxxxxx>]

On Tue, 21 Aug 2007, 3APA3A wrote:

>   6.   Ivan   Niiiil  (http://uNkn0wn.eu)  reports  vulnerabilities  in
>   Linkliste  1.2,  Butterfly online vistors counter 1.08, mcLinksCounter
>   1.2, My_REFERER 1.08.
>
>   Original messages in English are available from
>   http://securityvulns.com/source26994.html

This issue, originally reported in CVE-2006-4863 for 1.1, was disputed by
CVE and another party because langfile was set to a hard-coded value
(english.php) before the include statement.

For 1.2, there's a different hard-coded value (french.php) but the issue
seems to be the same.  From stats.php in 1.2 we have:

  include "mclc.php";
  include "$langfile";

and mclc.php has the interesting idiom:

  if (!empty($_GET)) { extract($_GET, EXTR_OVERWRITE); }

whose security implications should be immediately apparent to PHP
aficionados everywhere.  (I refer to this as a "variable extraction
error", CWE-621).

However, after this code, we have:

         $langfile="french.php";

french.php itself has no include/require code.

So, if this issue is legitimate, it would be useful to know how this
exploit works.


Thanks,
Steve