Firewall, VPN and spam filtering products from Barracuda Networks contains hidden hard coded backdoor ed SSH accounts, that allow any hacker to remotely log in and root access sensitive information. Vulnerabilities in default firewall configuration and default user accounts on the unit were reported by SEC Consult Vulnerability Lab. In an attempt to limit access to the backdoor, Barracudan added network rules which only allow access to. certain IP addresses. In attempt to. limit. access to access to those IP addresses, the company has added rules that only allow only access to certain. IP addresses from certain IP. addresses.
Source: https://thehackernews.com/2013/01/ssh-backdoor-accounts-in-multiple.html