2.1.3 Ensure dhcp server services are not in use

Information

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.

Unless a system is specifically set up to act as a DHCP server, it is recommended that this package be removed to reduce the potential attack surface.

Solution

Run the following commands to stop isc-dhcp-server.service and isc-dhcp-server6.service and remove the isc-dhcp-server package:

# systemctl stop isc-dhcp-server.service isc-dhcp-server6.service
# apt purge isc-dhcp-server

- OR -

- IF - the isc-dhcp-server package is required as a dependency:

Run the following commands to stop and mask isc-dhcp-server.service and isc-dhcp-server6.service :

# systemctl stop isc-dhcp-server.service isc-dhcp-server6.service
# systemctl mask isc-dhcp-server isc-dhcp-server6.service

Impact:

There may be packages that are dependent on the isc-dhcp-server package. If the isc-dhcp-server package is removed, these dependent packages will be removed as well. Before removing the isc-dhcp-server package, review any dependent packages to determine if they are required on the system.

- IF - a dependent package is required: stop and mask the isc-dhcp-server.service and isc-dhcp-server6.service leaving the isc-dhcp-server package installed.

See Also

https://workbench.cisecurity.org/benchmarks/20741

Item Details

Category: CONFIGURATION MANAGEMENT

References: 800-53|CM-6, 800-53|CM-7, CSCv7|9.2

Plugin: Unix

Control ID: 08900efa90c8d3857a6eafab2715dd0df62f9b672f9750827b0f93c5d145ffa2