Information
Verify that the TLS CA certificate file (the file that is passed alongwith --tlscacert parameter) has permissions of 444 or more restrictive.
Rationale:
The TLS CA certificate file should be protected from any tampering. It is used to authenticate Docker server based on given CA certificate. Hence, it must have permissions of 444 to maintain the integrity of the CA certificate.
Solution
chmod 444 <path to TLS CA certificate file>
This would set the file permissions of the TLS CA file to 444.
Impact:
None.
Default Value:
By default, the permissions for TLS CA certificate file might not be 444. The default file permissions are governed by the system or user specific umask values.