Security Advisory - Curesec Research Team

1. Introduction

Affected Product:    dotclear 2.8.1
Fixed in:            2.8.2
Fixed Version Link:  http://download.dotclear.org/latest.zip
Vendor Website:      http://dotclear.org/
Vulnerability Type:  XSS
Remote Exploitable:  Yes
Reported to vendor:  10/02/2015
Disclosed to public: 11/13/2015
Release mode:        Coordinated release
CVE:                 n/a
Credits              Tim Coen of Curesec GmbH

2. Overview

CVSS

Low 2.6 AV:N/AC:H/Au:N/C:N/I:P/A:N

Description

The Comment author name is echoed inside the value attribute of an input tag
when viewing the list of all comments for that author. Quotes are not encoded,
which allows for the addition of further attributes to the tag.

The field is hidden, so onfocus or similar do not work, and the length of the
name is limited, which makes an actual exploitation unlikely. Still, with older
browser an attacker might try to inject a style attribute which may lead to
XSS.

3. Proof of Concept


1. Create comment with author name
    " newattribute="value
2. Visit
    http://localhost/dotclear/admin/comments.php?n=30&status=&sortby=comment_dt&order=desc&author=%22+newattribute%3D%22value
3. The result will be:
    <input type="hidden" name="author" value="" newattribute="value"  />

4. Solution

To mitigate this issue please upgrade at least to version 2.8.2:

http://download.dotclear.org/latest.zip

Please note that a newer version might already be available.

5. Report Timeline

10/02/2015 Informed Vendor
10/25/2015 Vendor releases fix
11/13/2015 Disclosed to public


Blog Reference:
http://blog.curesec.com/article/blog/dotclear-281-XSS-94.html