Ensure mail transfer agent is configured for local-only mode

MoyenneNiveau 1Automatiséeros

Description

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. The audit requires nothing to listen on port 25 except 127.0.0.1 and ::1 (ss). Host-level control from the CIS ROS Melodic benchmark (Ubuntu 18.04 robot hosts); run as root.

Méthode de vérification

Méthode d'audit: Commande shell

shell

command -v ss >/dev/null 2>&1 || exit 1
l=$(ss -Hlntu 2>/dev/null | awk '$5 ~ /:25$/ {print $5}' | grep -Ev '^(127\.0\.0\.1|\[::1\]|::1):25$')
[ -z "$l" ] && echo compliant || echo "MTA listening on: $(printf '%s ' $l)"

Sortie attendue: compliant

Méthode de correction

Méthode de correction: Recommandation ou correctif d'infrastructure

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

Propriétés

Systèmes d'exploitation: Tous
Étiquettes: rosros1melodicservices
Référence: CIS ROS Melodic Benchmark v1.0.0 - 2.2.15 Ensure mail transfer agent is configured for local-only mode

Vérifier cet hôte

Exécutez cette commande sur une machine que vous êtes autorisé à auditer. L'analyse est en lecture seule.

shell

tmaegis scan --target ros