Re: Re: php-nuke again ...

[Melvyn Sopacua <msopacua () idg nl>]

At 09:25 1/21/2003, Pawel Kaczor wrote:

> on wed, 15 jan 2003, karol wiêsek wrote:
>
> > snip from mailatach.php
> >
> > if (isset($userfile) and $userfile != "none") {
> >     if (ini_get(file_uploads) and $attachments == 1) {
> >       $updir = "tmp";
> >       @copy($userfile, "$updir/$userfile_name");
> >
> > sample attack which allows an attacker to grab database password
> > and login.
> >
> > http://target.server/modules/webmail/mailattach.php?
> > userfile=../../config.php&userfile_name=../attachments/file.txt&
> > attachments=1
>
> i wasn't able to provide this attack succssefully but there's easy way of
> prevention - one can put those lines at the beginning of mailattach.php
> file:
>
> if (eregi("mailattach.php",$php_self)) {
>     header("location: ../../index.php");
>     die();
> }

Please - that is not a fix, but a delay of problems. $userfile should be 
verified
as being an uploaded file. The best way is to break php3 compatibility, drop
the register_globals requirement and use the $_FILES array and/or functions
like is_uploaded_file, which are created for the purpose. This assumes that
the content and extension of the file is not important - ie user-input 
validation,
which is the general implementation error plagueing php-nuke throughout the
entire source.

Given it's trackrecord, uninstalling php-nuke is probably the longterm 
solution.


Met vriendelijke groeten / With kind regards,

Webmaster IDG.nl
Melvyn Sopacua

<@Logan> I spent a minute looking at my own code by accident.
<@Logan> I was thinking "What the hell is this guy doing?"

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