pam_getenv: 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/sbin/pam_getenv - from package: libpam-runtime

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