Ensure sshd MACs are configured

ÉlevéeNiveau 1Automatiséefreebsd

Description

This variable limits the types of MAC algorithms that SSH can use during communication. Notes: Some organizations may have stricter requirements for approved MACs. Ensure that MACs used are in compliance with site policy. The only "strong" MACs currently FIPS 140-2 approved are: o HMAC-SHA1 o HMAC-SHA2-256 o HMAC-SHA2-384 o HMAC-SHA2-512 Audit: the effective `macs` list from `sshd -T` must not contain any weak algorithm listed by CIS.

Méthode de vérification

Méthode d'audit: Commande shell

shell

command -v sshd >/dev/null 2>&1 || exit 1; out=$(sshd -T 2>/dev/null) || exit 1; line=$(printf '%s\n' "$out" | grep -i '^macs '); [ -n "$line" ] || exit 1; printf '%s\n' "$line" | grep -Eiq -- '(^|[ ,])(hmac-md5|hmac-md5-96|hmac-ripemd160|hmac-sha1-96|umac-64@openssh\.com|hmac-md5-etm@openssh\.com|hmac-md5-96-etm@openssh\.com|hmac-ripemd160-etm@openssh\.com|hmac-sha1-96-etm@openssh\.com|umac-64-etm@openssh\.com|umac-128-etm@openssh\.com)(,|$)' && echo "weak: $line" || echo compliant

Sortie attendue: compliant

Méthode de correction

Méthode de correction: Recommandation ou correctif d'infrastructure

Edit the /etc/ssh/sshd_config file and add/modify the MACs line to contain a comma separated list of the site unapproved (weak) MACs preceded with a - above any Include entries: Example: MACs -hmac-md5,hmac-md5-96,hmac-ripemd160,hmac-sha1-96,umac- 64@openssh.com,hmac-md5-etm@openssh.com,hmac-md5-96-etm@openssh.com,hmac- ripemd160-etm@openssh.com,hmac-sha1-96-etm@openssh.com,umac-64- etm@openssh.com

Propriétés

Systèmes d'exploitation: Tous
Étiquettes: freebsdssh
Référence: CIS FreeBSD 14 Benchmark v1.0.1 - 4.2.14 Ensure sshd MACs are configured

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 freebsd