SYSS-2015-033: Missing Function Level Access Control (CWE-935) in Page2Flip Premium App 2.5

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Advisory ID: SYSS-2015-033
Product: Page2Flip
Vendor: w!ssenswerft GmbH
Affected Version(s): Premium App 2.5, probably also in Business App
and Basic App, and in lower versions
Tested Version(s): Premium App 2.5
Vulnerability Type: Missing Function Level Access Control (CWE-935)
Risk Level: High
Solution Status: Open
Vendor Notification: 2015-06-29
Solution Date:
Public Disclosure:
CVE Reference: Not yet assigned
Author of Advisory: Dr. Erlijn van Genuchten (SySS GmbH)

Overview:

With the Page2Flip Web application, it is possible to create e-papers in
PDF format that can be flicked through digitally. Such e-papers can be
used for magazines, catalogues, flyers, etc. (see [1]).

The Page2Flip app allows users to access functionality that should only 
be available for administrative users.

Vulnerability Details:

The SySS GmbH identified that it is possible for a user with low
privileges, to access functionality that should only be accessible by
administrators, by directly entering the URL.

Proof of Concept (PoC):

For example, by accessing the URL https://[host]/settings/users, all 
user names and e-mail addresses can be accessed. Also, by accessing the 
URL https://[host]/settings/extended, it is possible to perform the same 
actions as high privileged users are able to perform.

Solution:

Disclosure Timeline:

2015-06-23: Vulnerability discovered
2013-06-29: Vulnerability reported to vendor
2015-07-07: Reported vulnerabilities again as the vendor did not respond 
            to the first e-mail
2015-07-14: Reminder sent concerning reported vulnerabilities
2015-08-24: Public release of security advisory according to the SySS
            Responsible Disclosure Policy

References:

[1] Page2Flip homepage
http://page2flip.de/
[2] SySS Responsible Disclosure Policy
https://www.syss.de/en/news/responsible-disclosure-policy/

Credits:

Security vulnerability found by Responsible Hacker of the SySS GmbH.

E-Mail: erlijn.vangenuchten@syss.de
Public Key: https://www.syss.de/fileadmin/dokumente/Materialien/PGPKeys/Erlijn_vanGenuchten.asc
Key ID: 0xBD96FF2A
Key Fingerprint: 17BB 4CED 755A CBB3 2D47 C563 0CA5 8637 BD96 FF2A

Disclaimer:

The information provided in this security advisory is provided "as is"
and without warranty of any kind. Details of this security advisory may
be updated in order to provide as accurate information as possible. The
latest version of this security advisory is available on the SySS Web
site.

Copyright:

Creative Commons - Attribution (by) - Version 3.0
URL: http://creativecommons.org/licenses/by/3.0/deed.en
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