cdvpasswd: command not found

Have You tried accessing the binary with the full path?

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/cdvpasswd - from package: codeville

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