PPCal Shopping Cart XSS

PPCal Shopping Cart XSS

Vuln. discovered by : r0t
Date: 15 dec. 2005
orginal advisory:http://pridels.blogspot.com/2005/12/ppcal-shopping-cart-xss.html
vendor:http://www.paypalshoppingcart.org/
affected version:3.3.0 and prior

Product Description:

PPCal Shopping Cart allows integration and automation of PayPal
payments on your web site. Applications are numerous. PPCal can be
easily customized to serve any purpose, associated with PayPal
payment.

Vuln. Description:

PPCal Shopping Cart contains a flaw that allows a remote cross site
scripting attack. This flaw exists because input passed "stop" "user"
paremters isn't properly sanitised before being returned to the user.
This could allow a user to create a specially crafted URL that would
execute arbitrary code in a user's browser within the trust
relationship between the browser and the server, leading to a loss of
integrity.

examples:
/ppcal.cgi?action=shop&user=8001&start=21
&stop=%22%3E%3Cscript%3Ealert('r0t')%3C
/script%3E

/ppcal.cgi?action=shop&user=%22%3E%3Cscri
pt%3Ealert('r0t')%3C/script%3E

Solution:
Edit the source code to ensure that input is properly sanitised.