Cis Ubuntu1804 V220 2 1 2 3

2.1.2.3 Ensure chrony is enabled and running (Automated)

Profile

• Level 1 - Server
• Level 1 - Workstation

Description

chrony is a daemon for synchronizing the system clock across the network.

Rationale

chrony needs to be enabled and running in order to synchronize the system to a timeserver.

Time synchronization is important to support time sensitive security mechanisms and to ensure log files have consistent time records across the enterprise to aid in forensic investigations.

Audit Procedure

Command Line

IF chrony is in use on the system, run the following commands:

Run the following command to verify that the chrony service is enabled:

# systemctl is-enabled chrony.service
enabled

Run the following command to verify that the chrony service is active:

# systemctl is-active chrony.service
active

Expected Result

• systemctl is-enabled chrony.service returns enabled
• systemctl is-active chrony.service returns active

Remediation

Command Line

IF chrony is in use on the system, run the following commands:

Run the following command to unmask chrony.service:

# systemctl unmask chrony.service

Run the following command to enable and start chrony.service:

# systemctl --now enable chrony.service

OR

If another time synchronization service is in use on the system, run the following command to remove chrony:

# apt purge chrony

References

1. NIST SP 800-53 Rev. 5: AU-8

CIS Controls

• v8: 8.4 - Standardize Time Synchronization
• v7: 6.1 - Utilize Three Synchronized Time Sources