[SYSS-2015-026] Denial of Service (CWE-730) and Overly Restrictive Account Lockout Mechanism (CWE-645) in Page2Flip Premium App 2.5

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Advisory ID: SYSS-2015-026
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: Denial of Service (CWE-730)
Overly Restrictive Account Lockout Mechanism (CWE-645)
Risk Level: Medium
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 application is vulnerable to denial-of-service attacks
against user accounts.

Vulnerability Details:

The SySS GmbH identified a denial-of-service vulnerability in the user
login functionality. When for a user account, a wrong password has been
entered five times, this user account is locked.

This user account cannot be unlocked by an administrative user, nor is
it automatically unlocked after at least 12 hours.

Proof of Concept (PoC):

Enter for an existing e-mail address a wrong password five times.

Solution:

Disclosure Timeline:

2015-06-23: Vulnerability discovered
2015-06-29: 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:

This security vulnerability was found by Dr. Erlijn van Genuchten 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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