RHEL-10-800300 - RHEL 10 must configure a DNS processing mode in Network Manager to avoid conflicts with other Domain Name Server (DNS) managers and to not leak DNS queries to untrusted networks.

Information

To ensure that DNS resolver settings are respected, a DNS mode in Network Manager must be configured. The following are common DNS values in "NetworkManager.conf [main]":

- default: NetworkManager will update "/etc/resolv.conf" to reflect the nameservers provided by currently active connections.
- none: NetworkManager will not modify "/etc/resolv.conf". Used when DNS is managed manually or by another service.
- systemd-resolved: Uses "systemd-resolved" to manage DNS.
- dnsmasq: Enables the internal "dnsmasq" plugin.

Satisfies: SRG-OS-000420-GPOS-00186, SRG-OS-000142-GPOS-00091

Solution

Configure RHEL 10 to use a DNS mode in Network Manager.

In "/etc/NetworkManager/NetworkManager.conf", add the following line in the "[main]" section:

dns = none

Where <dns processing mode> is default, none, or systemd-resolved.

Network Manager must be reloaded for the change to take effect:

$ sudo systemctl reload NetworkManager

See Also

https://dl.dod.cyber.mil/wp-content/uploads/stigs/zip/U_RHEL_10_V1R1_STIG.zip

Item Details

Category: SYSTEM AND COMMUNICATIONS PROTECTION

References: 800-53|SC-5, 800-53|SC-7(9), CAT|II, CCI|CCI-001115, CCI|CCI-002385, Rule-ID|SV-281362r1167236_rule, STIG-ID|RHEL-10-800300, Vuln-ID|V-281362

Plugin: Unix

Control ID: e774ffd9542b51168be7fcfd0b852c9492fcb63308369f6d10d722ff9f7a7803