Cross-site scripting (XSS) vulnerability in index.php in Google API Search 1.3.1 and earlier allows remote attackers to inject arbitrary web script or HTML via hex-encoded values in the REQ parameter.
https://exchange.xforce.ibmcloud.com/vulnerabilities/23347
http://www.vupen.com/english/advisories/2005/2608
http://www.securityfocus.com/bid/15612
http://secunia.com/advisories/17725
http://pridels0.blogspot.com/2005/11/google-api-search-xss-vuln.html