CubeCart contain a flaw that allows a remote cross site scripting attack.  This flaw exists because the application does not validate the "_a" (when "searchStr" is set) and "Submit" variables upon submission to the index.php script.  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.

References:

CVE-2008-1550

Secunia: 29532

SecWatch

Vendor Solution