Hello Bugtraq!

I want to warn you about security vulnerabilities in system phpCOIN.

-----------------------------
Advisory: Vulnerabilities in phpCOIN
-----------------------------
URL: http://websecurity.com.ua/4090/ 
-----------------------------
Affected products: phpCOIN 1.6.5 and previous versions.
-----------------------------
Timeline:
17.03.2010 - found vulnerabilities.
01.04.2010 - disclosed at my site.
02.04.2010 - 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/coin_addons/captcha/CaptchaSecurityImages.php?width=150&height=100&characters=2 

Captcha bypass is possible via half-automated or automated (with using of
OCR) methods, which were mentioned before (http://websecurity.com.ua/4043/). 

DoS:

http://site/coin_addons/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