ubiattach: 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/sbin/ubiattach - from package: mtd-utils

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

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