cdfvint: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/bin/cdfvint - from package: cdftools

You may install the required package with command apt-get install {package}

Error in other languages:
cdfvint: bevel nie gevind nie
cdfvint: comandă negăsită
cdfvint: comando não encontrado
cdfvint: commande introuvable
cdfvint: command not found
cdfvint: käsku ei ole
cdfvint: không tìm thấy lệnh
cdfvint: komanda nerasta
cdfvint: Kommando nicht gefunden.
cdfvint: kommandot finns inte
cdfvint: komut yok
cdfvint: nie znaleziono polecenia
cdfvint: níor aimsíodh an t-ordú
cdfvint: no se encontró la orden
cdfvint: no s'ha trobat l'ordre
cdfvint: opdracht niet gevonden
cdfvint: parancs nem található
cdfvint: perintah tidak ditemukan
cdfvint: príkaz nenájdený
cdfvint: příkaz nenalezen
cdfvint: команда не найдена
cdfvint: командата не е открита
cdfvint: 命令找不到
cdfvint: コマンドが見つかりません