Ensure mail transfer agent is configured for local-only mode

MediaNivel 1Automatizadalinux

Descripción

Mail Transfer Agents (MTA), such as sendmail and Postfix, are used to listen for incoming mail and transfer the messages to the appropriate user or mail server. If the system is not intended to be a mail server, it is recommended that the MTA be configured to only process local mail.

Cómo se verifica

Método de auditoría: Comando de shell

shell

alt0() { command -v grep >/dev/null 2>&1 || { echo "step1: grep not installed"; return 1; }; command -v netstat >/dev/null 2>&1 || { echo "step1: netstat not installed"; return 1; }; o=$(bash -c 'netstat -an | grep LIST | grep ":25[[:space:]]"' 2>&1); printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- 'tcp 0 0 127.0.0.1:25 0.0.0.0:* LISTEN' || { echo step1: missing 'tcp 0 0 127.0.0.1:25 0.0.0.0:* LISTEN'; return 1; }; }; if alt0; then echo compliant; fi

Salida esperada: compliant

Cómo se corrige

Método de corrección: Guía o parche de infraestructura

Edit /etc/postfix/main.cf and add the following line to the RECEIVING MAIL section. If the line already exists, change it to look like the line below: inet_interfaces = loopback-only Restart postfix: # systemctl restart postfix

Propiedades

Sistemas operativos: alinux-2
Etiquetas: cis-convertedlinux
Referencia: CIS Aliyun Linux 2 Benchmark v1.0.0 ARCHIVE - 2.1.15

Verificar este host

Ejecute esto en un equipo que tenga permiso para auditar. El escaneo es de solo lectura.

shell

tmaegis scan --target linux