2.2.2 Ensure avahi daemon services are not in use

Information

Avahi is a free zeroconf implementation, including a system for multicast DNS/DNS-SD service discovery. Avahi allows programs to publish and discover services and hosts running on a local network with no specific configuration. For example, a user can plug a computer into a network and Avahi automatically finds printers to print to, files to look at and people to talk to, as well as network services running on the machine.

Automatic discovery of network services is not normally required for system functionality. It is recommended to remove this package to reduce the potential attack surface.

Solution

Run the following commands to stop avahi-daemon.socket and avahi-daemon.service and remove the avahi package:

# systemctl stop avahi-daemon.socket avahi-daemon.service
# yum remove avahi

-OR-

-IF- the avahi package is required as a dependency:

Run the following commands to stop and mask the avahi-daemon.socket and avahi-daemon.service :

# systemctl stop avahi-daemon.socket avahi-daemon.service
# systemctl mask avahi-daemon.socket avahi-daemon.service

Impact:

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

-IF- a dependent package is required: stop and mask the avahi-daemon.socket and avahi-daemon.service leaving the avahi package installed.

See Also

https://workbench.cisecurity.org/benchmarks/15964

Item Details

Category: CONFIGURATION MANAGEMENT

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

Plugin: Unix

Control ID: edb839dfcb59d3eb5398245b3556cbc6c81bcf30f99b8b15532f43c93b85aef9