SQL injection vulnerability in index.php in Relative Real Estate Systems 3.0 and earlier allows remote attackers to execute arbitrary SQL commands via the listing_id parameter in a listings action.
https://www.exploit-db.com/exploits/5924
https://exchange.xforce.ibmcloud.com/vulnerabilities/43316
http://www.vupen.com/english/advisories/2008/1926/references
http://www.securityfocus.com/archive/1/493663/100/0/threaded