certutil: 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 CentOS possible default full paths are:

/usr/bin/certutil - from package: nss-tools

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/certutil - from package: libnss3-tools

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

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