Cisco Unity 2.x and 3.x uses well-known default user accounts, which could allow remote attackers to gain access and place arbitrary calls.Referenceshttps://exchange.xforce.ibmcloud.com/vulnerabilities/44545http://www.iss.net/security_center/static/10282.phphttp://www.cisco.com/warp/public/707/toll-fraud-pub.shtml
