Vulnerabilities in Sebo - webstore

["MustLive" <mustlive () websecurity com ua>]

Hello Bugtraq!

I want to warn you about security vulnerabilities in e-commerce system
Sebo - webstore.

In this advisory I'm continue to inform readers of mailing lists about
vulnerable web applications which are using CaptchaSecurityImages.php. If
you read Bugtraq you can saw the letter, from which it's clearly seen, that
web developers ignore advisory about holes in CaptchaSecurityImages.php
itself, and only draw attention on advisories about their specific web
applications. And I answered on this letter
(http://www.securityfocus.com/archive/1/511023). So, as I already wrote to
the list, it's only way to draw attention of web developers to these issues.

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Advisory: Vulnerabilities in Sebo - webstore
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URL: http://websecurity.com.ua/4108/
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Affected product: Sebo - webstore 0.14 and previous versions.
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Timeline:

17.03.2010 - found vulnerabilities.
08.04.2010 - disclosed at my site.
09.04.2010 - informed developers.
-----------------------------
Details:

These are Insufficient Anti-automation and Denial of Service
vulnerabilities.

The vulnerabilities exist in captcha script CaptchaSecurityImages.php, which
is using in this system. I already reported about vulnerabilities in
CaptchaSecurityImages (http://websecurity.com.ua/4043/).

Insufficient Anti-automation:

http://site/libs/captcha/CaptchaSecurityImages.php?width=150&height=100&characters=2

Captcha bypass is possible as via half-automated or automated (with using of
OCR) methods, which were mentioned before (http://websecurity.com.ua/4043/),
as with using of session reusing with constant captcha bypass method
(http://websecurity.com.ua/1551/), which was described in project Month of
Bugs in Captchas. Last variant of attack is possible due to incorrect
implementation of protection in the system against this captcha bypass
method.

DoS:

http://site/libs/captcha/CaptchaSecurityImages.php?width=1000&height=9000

With setting of large values of width and height it's possible to create
large load at the server.

Best wishes & regards,
MustLive
Administrator of Websecurity web site
http://websecurity.com.ua