TMA-FREEBSD-4.2.6

Ensure sshd Ciphers are configured

AltaNivel 1Automatizadafreebsd

Descripción

This variable limits the ciphers that SSH can use during communication. Note: Some organizations may have stricter requirements for approved ciphers. Ensure that ciphers used are in compliance with site policy. The only "strong" ciphers currently FIPS 140-2 compliant are: o aes256-ctr o aes192-ctr o aes128-ctr Audit: the effective `ciphers` list from `sshd -T` must not contain any weak algorithm listed by CIS.

Cómo se verifica

Método de auditoría: Comando de shell

shell

command -v sshd >/dev/null 2>&1 || exit 1; out=$(sshd -T 2>/dev/null) || exit 1; line=$(printf '%s\n' "$out" | grep -i '^ciphers '); [ -n "$line" ] || exit 1; printf '%s\n' "$line" | grep -Eiq -- '(^|[ ,])((3des|blowfish|cast128|aes(128|192|256))-cbc|arcfour(128|256)?|rijndael-cbc@lysator\.liu\.se)(,|$)' && echo "weak: $line" || echo compliant

Salida esperada: compliant

Cómo se corrige

Método de corrección: Guía o parche de infraestructura

Edit the /etc/ssh/sshd_config file and add/modify the Ciphers line to contain a comma separated list of the site unapproved (weak) Ciphers preceded with a - above any Include entries: Example: Ciphers -3des-cbc,aes128-cbc,aes192-cbc,aes256-cbc,rijndael- cbc@lysator.liu.se

Propiedades

Sistemas operativos: Cualquiera
Etiquetas: freebsdssh
Referencia: CIS FreeBSD 14 Benchmark v1.0.1 - 4.2.6 Ensure sshd Ciphers are configured

Verificar este host

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

shell

tmaegis scan --target freebsd