TMA-FREEBSD-4.2.9

Ensure sshd HostbasedAuthentication is disabled

HighLevel 1Automatedfreebsd

Description

The HostbasedAuthentication parameter specifies if authentication is allowed through trusted hosts via the user of .rhosts, or /etc/hosts.equiv, along with successful public key client host authentication. Even though the .rhosts files are ineffective if support is disabled in /etc/pam.conf, disabling the ability to use .rhosts files in SSH provides an additional layer of protection. Audit: evaluates the effective configuration from `sshd -T` (Match blocks must be reviewed separately).

How it is checked

Audit method: Shell command

shell

command -v sshd >/dev/null 2>&1 || exit 1; out=$(sshd -T 2>/dev/null) || exit 1; r=compliant; for p in '^hostbasedauthentication[[:blank:]]+no$'; do printf '%s\n' "$out" | grep -Eiq -- "$p" || r="not matched: $p"; done; echo "$r"

Expected output: compliant

How it is fixed

Fix method: Guidance or infrastructure patch

Edit the /etc/ssh/sshd_config file to set the parameter above any Include entries as follows: HostbasedAuthentication no

Properties

Operating systems: Any
Tags: freebsdssh
Reference: CIS FreeBSD 14 Benchmark v1.0.1 - 4.2.9 Ensure sshd HostbasedAuthentication is disabled

Check this host

Run this on a machine you are allowed to audit. The scan is read-only.

shell

tmaegis scan --target freebsd