man cssh гласит: Connections are opened via ssh so a correctly installed and configured ssh installation is required. If, however, the program is called by "crsh" then the rsh protocol is used (and the communications channel is insecure), or by "ctel" then telnet is used. Но команд crsh и ctel нет. Нужно добавить соответствующие линки (символические или жесткие?) на программу cssh.
Fixed in 3.24-alt2.
Забыл тыкнуть кнопачге.