Advisory Name: Multiple Persistent Cross-Site Scripting (XSS) in Front Accounting
Internal Cybsec Advisory Id: 2010-1001-Multiple Persistent XSSs in Front Accounting

Vulnerability Class: Permanent Cross-Site Scripting (XSS)

Release Date: 10/29/2010

Affected Applications: Front Accounting v2.3RC2; other versions may also be affected.

Affected Platforms: Any running Front Accounting v2.3RC2

Local / Remote: Remote

Severity: High - CVSS: 5.8 (AV:N/AC:M/Au:NR/C:N/I:P/A:P)

Researcher: Juan Manuel Garcia

Vendor Status: Acknowedged

Reference to Vulnerability Disclosure Policy: http://www.cybsec.com/vulnerability_policy.pdf

Vulnerability Description:

Multiple Persistent Cross-Site vulnerabilities were found in Front Accounting v2.3RC2, because the

application fails to sanitize the response before it is returned to the user. This can be exploited to

execute arbitrary script and HTML code in a user's browser session. This may allow the attacker to

steal the user's cookie and to launch further attacks.

The parameter 'trans_no' in /purchasing/allocations/supplier_allocate.php is not properly sanitized.

The parameter 'PONumber' in /purchasing/po_receive_items.php is not properly sanitized.

Other parameters might also be affected.

Proof of Concept:

* The parameter 'trans_no' in the POST request has been set to:

<script>alert(165602)</script>

GET /purchasing/allocations/supplier_allocate.php?trans_type=1 HTTP/1.0

Cookie: FA4649d6f070639b67129c222b2094650d=2aa6f7cc954528a151a5f5d6c658f418

Accept: */*

Accept-Language: en-US

User-Agent: Mozilla/4.0 (compatible; MSIE 6.0; Win32)

Host: next.frontaccounting.eu

Referer: http://next.frontaccounting.eu/purchasing/allocations/supplier_allocation_main.php

* The parameter 'PONumber' in the POST request has been set to:

<script>alert(188214)</script>

GET /purchasing/po_receive_items.php?PONumber= HTTP/1.0

Cookie: FA4649d6f070639b67129c222b2094650d=2aa6f7cc954528a151a5f5d6c658f418

Accept: */*

Accept-Language: en-US

User-Agent: Mozilla/4.0 (compatible; MSIE 6.0; Win32)

Host: next.frontaccounting.eu

Referer: http://next.frontaccounting.eu/purchasing/inquiry/po_search.php

Impact:

An affected user may unintentionally execute scripts or actions written by an attacker. In addition, an

attacker may obtain authorization cookies that would allow him to gain unauthorized access to the

application.

Solution:

Upgrade to FrontAccounting v2.3RC3

Vendor Response:

2010-10-12 - Vulnerability was identified

2010-10-13 - Vendor contacted

10/16/2010 Vendor confirmed vulnerability

10/19/2010 Vendor says that the bug will we fixed in FrontAccounting v2.3RC3

10/29/2010 Vulnerability was released

Contact Information:

For more information regarding the vulnerability feel free to contact the researcher at

jmgarcia <at> cybsec <dot> com

About CYBSEC S.A. Security Systems

Since 1996, CYBSEC is engaged exclusively in rendering professional services specialized in

Information Security. Their area of services covers Latin America, Spain and over 250 customers are a

proof of their professional life.

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software and/or hardware provider companies.

Our services are strictly focused on Information Security, protecting our clients from emerging security

threats, maintaining their IT deployments available, safe, and reliable.

Beyond professional services, CYBSEC is continuously researching new defense and attack techniques

and contributing with the security community with high quality information exchange.

For more information, please visit www.cybsec.com

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