Serendipity Input Validation Flaws in Administration Interface Permit Cross-Site Scripting Attacks
SecurityTracker Alert ID: 1017100|
SecurityTracker URL: http://securitytracker.com/id/1017100
(Links to External Site)
Updated: Jun 2 2008|
Original Entry Date: Oct 20 2006
Disclosure of authentication information, Disclosure of user information, Execution of arbitrary code via network, Modification of user information|
Fix Available: Yes Vendor Confirmed: Yes |
Version(s): 1.0.1 and prior versions|
A vulnerability was reported in Serendipity. A remote user can conduct cross-site scripting attacks.|
The web administration interface does not properly filter HTML code from user-supplied input before displaying the input. A remote user can create a specially crafted URL that, when loaded by a target administrative user, will cause arbitrary scripting code to be executed by the target user's browser. The code will originate from the site running the Serendipity software and will run in the security context of that site. As a result, the code will be able to access the target user's cookies (including authentication cookies), if any, associated with the site, access data recently submitted by the target user via web form to the site, or take actions on the site acting as the target user.
The media manager administration page is affected.
The vendor was notified on October 5, 2006.
Stefan Esser of the Hardened-PHP Project reported this vulnerability.
The original advisory is available at:
A remote user can access the target administrative user's cookies (including authentication cookies), if any, associated with the site running the Serendipity software, access data recently submitted by the target user via web form to the site, or take actions on the site acting as the target user.|
The vendor has issued a fixed version (1.0.2), available at:|
Vendor URL: www.s9y.org/ (Links to External Site)
Input validation error|
|Underlying OS: Linux (Any), UNIX (Any), Windows (Any)|
Source Message Contents
Subject: Advisory 11/2006: Serendipity Weblog XSS Vulnerabilities|
-----BEGIN PGP SIGNED MESSAGE-----
-= Security Advisory =-
Advisory: Serendipity Weblog XSS Vulnerabilities
Release Date: 2006/10/19
Last Modified: 2006/10/19
Author: Stefan Esser [firstname.lastname@example.org]
Application: Serendipity <= 1.0.1
Severity: Multiple XSS vulnerabilities within the administration
interface allow Cross Site Scripting attacks against
the blog admin
Vendor Status: Vendor has a released an updated version
Quote from http://www.s9y.org
"Serendipity is a PHP-powered weblog application which gives the
user an easy way to maintain an online diary, weblog or even a
complete homepage. While the default package is designed for
the casual blogger, Serendipity offers a flexible, expandable
and easy-to-use framework with the power for professional
During an quick audit of Serendipity it was discovered that
multiple XSS vulnerabilities exist in the administration area.
Because of this vulnerabilities it is possible for an attacker
that tricks an admin into visiting a special prepared website
to perform any administrative action in the blog. This includes
posting entries or adding additional admin users.
Tricking a blog admin to visit a certain website is usually as
simple as mentioning an URL in the comments of his blog.
Serendipity failed to correctly sanitize user input on the
media manager administration page. The content of GET variables
evasion techniques it was possible to execute arbitrary
Additionally Serendipity dynamically created a HTML form on
the media manager administration page that contained all
variables found in the URL as hidden fields. While the variable
values were correctly escaped it was possible to break out
by specifying strange variable names.
Proof of Concept:
The Hardened-PHP Project is not going to release exploits for
this vulnerability to the public.
05. October 2006 - Contacted Serendipity developers by email
18. October 2006 - Updated Serendipity was released
19. October 2006 - Public Disclosure
It is strongly recommended to upgrade to the newest version of
Serendipity 1.0.2 which you can download at:
pub 1024D/0A864AA1 2004-04-17 Hardened-PHP Signature Key
Key fingerprint = 066F A6D0 E57E 9936 9082 7E52 4439 14CC 0A86 4AA1
Copyright 2006 Stefan Esser. All rights reserved.
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