. . .
._ | . .| . .;/
[)|(]\|[ )(](.| \.net
| ._|
"YA Book 0.98-alpha - Persistent XSS Vulnerability"
by Omni

1) Infos

Date : 2007-04-23
Product : YA Book
Version : 0.98-alpha - Prior version maybe also be affected
Vendor : http://sourceforge.net/projects/yabook - http://www.phpee.com/
Vendor Status : 2007-04-23 -> Not Informed!
2007-04-24 -> Informed!

Description : YaBook- Ya Book! …or yet another guestbook. YaBook is a simple but powerful guestbook running on PHP
5. It features easy installation and customization, multi-language support, and an administration
interface. Various database systems are supported.

Google Dork : Powered by YaBook 0.98-alpha - "Powered by YaBook 0.98-alpha"

Source : omnipresent - omni
E-mail : omnipresent[at]email[dot]it - omni[at]playhack[dot]net
Team : Playhack.net Security

2) Security Issues

— [ Remote Persistent XSS ] —

YA Book is vulnerable to an XSS. A malicous user can put in the City Field HTML or JS code
(in sigin module: http://host/path/index.php?mode=sign) as shown below:

Eg script:

<script>alert("XSS")</script>

The vulnerability exist because the city field is not properly sanitized before being used!

— [ PoC ] —

A guest can posts a new message and after put the right captcha :D he can puts in the city field a code like:

<script>location.href="http://host.com"</script>

for a redirect with JS or… he can injects other (eg: HTML, JS) codes…

3) Patch

Edit the source code to ensure that the input is properly sanitized before being used.