The remote host is missing an update to the system as announced in the referenced advisory FreeBSD-SA-06:09.openssh.asc
Upgrade your system to the appropriate stable release or security branch dated after the correction date https://secure1.securityspace.com/smysecure/catid.html?in=FreeBSD-SA-06:09.openssh.asc
OpenSSH is an implementation of the SSH protocol suite, providing an encrypted, authenticated transport for a variety of services, including remote shell access. Privilege separation is a mechanism used by OpenSSH to protect itself against possible future vulnerabilities. It works by splitting the server process in two: the child process drops its privileges and carries on the conversation with the client, while the parent retains its privileges, monitors the child, and performs privileged operations on behalf of the child when it is satisified that everything is in order. Privilege separation is enabled by default in FreeBSD. OpenPAM is an implementation of the PAM framework, which allows the use of loadable modules to implement user authentication and session management in a manner defined by the administrator. It is used by OpenSSH and numerous other applications in FreeBSD to provide a consistent and configurable authentication system. Because OpenSSH and OpenPAM have conflicting designs (one is event- driven while the other is callback-driven), it is necessary for OpenSSH to fork a child process to handle calls to the PAM framework. However, if the unprivileged child terminates while PAM authentication is under way, the parent process incorrectly believes that the PAM child also terminated. The parent process then terminates, and the PAM child is left behind. Due to the way OpenSSH performs internal accounting, these orphaned PAM children are counted as pending connections by the master OpenSSH server process. Once a certain number of orphans has accumulated, the master decides that it is overloaded and stops accepting client connections.