bum: 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/bum - from package: bum

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