On the BIND 9.x server the private key corresponding to the ZSK, stored on name servers accepting dynamic updates, must be group owned by root.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-207590 | BIND-9X-001411 | SV-207590r879887_rule | CCI-000366 | medium |
| Description | ||||
| The private ZSK key must be protected from unauthorized access. This strategy is not feasible in situations in which the DNSSEC-aware name server has to support dynamic updates. To support dynamic update transactions, the DNSSEC-aware name server (which usually is a primary authoritative name server) has to have both the zone file master copy and the private key corresponding to the zone-signing key (ZSK-private) online to immediately update the signatures for the updated RRsets. | ||||
| STIG | Date | |||
| BIND 9.x Security Technical Implementation Guide | 2024-02-15 | |||
Details
Check Text (C-207590r879887_chk)
If the server is in a classified network, this is Not Applicable.
Note: This check only verifies for ZSK key file ownership. Permissions for key files are required under V-72451, BIND-9X-001132 and V-72461, BIND-9X-001142.
For each signed zone file, identify the ZSK "key id" number:
# cat <signed_zone_file> | grep -i "zsk"
ZSK; alg = ECDSAP256SHA256; key id = 22335
Using the ZSK "key id", verify the private ZSK.
Kexample.com.+008+22335.private
Verify that the private ZSK is owned by root:
# ls -l <ZSK_key_file>
-r------- 1 root root 1776 Jul 3 17:56 Kexample.com.+008+22335.private
If the key file is not group owned by root, this is a finding.
Fix Text (F-7845r283825_fix)
Change the group ownership of the ZSK private key to the root group account.
# chgrp root <key_file>