dbsnmp in Oracle 8.1.6 and 8.1.7 uses the ORACLE_HOME environment variable to find and execute the dbsnmp program, which allows local users to execute arbitrary programs by pointing the ORACLE_HOME to an alternate directory that contains a malicious version of dbsnmp.
https://exchange.xforce.ibmcloud.com/vulnerabilities/7645
http://www.securityfocus.com/bid/3137