Ensure dhcp server services are not in use

MediumLevel 1Automatedlinux

Description

The Dynamic Host Configuration Protocol (DHCP) is a service that allows machines to be dynamically assigned IP addresses. There are two versions of the DHCP protocol DHCPv4 and DHCPv6. At startup the server may be started for one or the other via the -4 or -6 arguments.

How it is checked

Audit method: Shell command

shell

alt0() { command -v rpm >/dev/null 2>&1 || { echo "step1: rpm not installed"; return 1; }; o=$(bash -c 'rpm -q dhcp-server' 2>&1); printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- 'package dhcp-server is not installed' || { echo step1: missing 'package dhcp-server is not installed'; return 1; }; }; alt1() { command -v grep >/dev/null 2>&1 || { echo "step1: grep not installed"; return 1; }; command -v systemctl >/dev/null 2>&1 || { echo "step1: systemctl not installed"; return 1; }; o=$(bash -c 'systemctl is-enabled dhcpd.service dhcpd6.service 2>/dev/null | grep '"'"'enabled'"'"'' 2>/dev/null); [ -z "$o" ] || { echo "step1: $o" | head -c 300; return 1; }; command -v grep >/dev/null 2>&1 || { echo "step2: grep not installed"; return 1; }; command -v systemctl >/dev/null 2>&1 || { echo "step2: systemctl not installed"; return 1; }; o=$(bash -c 'systemctl is-active dhcpd.service dhcpd6.service 2>/dev/null | grep '"'"'^active'"'"'' 2>/dev/null); [ -z "$o" ] || { echo "step2: $o" | head -c 300; return 1; }; }; if alt0 || alt1; then echo compliant; fi

Expected output: compliant

How it is fixed

Fix method: Guidance or infrastructure patch

Run the following commands to stop dhcpd.service and dhcpd6.service and remove the dhcp-server package: # systemctl stop dhcpd.service dhcpd6.service # dnf remove dhcp-server - OR - - IF - the dhcp-server package is required as a dependency: Run the following commands to stop and mask dhcpd.service and dhcpd6.service: # systemctl stop dhcpd.service dhcpd6.service # systemctl mask dhcpd.service dhcpd6.service

Properties

Operating systems: rocky-9
Tags: cis-convertedlinux
Reference: CIS Rocky Linux 9 Benchmark v3.0.0 - 2.1.4

Check this host

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

shell

tmaegis scan --target linux