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Bind 389DS to specific IP addresses only to limit exposure.

389-NS-004 - severity: medium

Field Value
Control ID 389-NS-004
Severity medium
Type preventive
Owner IT Operations
Status authored
NIST 800-53 SC-7
DISA SRG SRG-APP-000142

Rationale

By default, 389 Directory Server binds nsslapd-listenhost and nsslapd-securelistenhost to all available interfaces (0.0.0.0), which means the LDAP and LDAPS ports are reachable on every network the host is connected to - including management, storage, or backup networks that have no legitimate need to carry directory traffic. An attacker or misconfigured client on any of those segments can reach the authentication service, probe the directory schema, or attempt bind attacks without traversing any firewall boundary. Restricting the listen address to a specific management or service IP eliminates that exposure at the process level, ensuring the directory is unreachable from unintended network segments even if host-based firewall rules are misconfigured or temporarily disabled. This implements the network-boundary protection principle of NIST SP 800-53 SC-7 and contributes to satisfying DISA SRG-APP-000142.

Check

Check which interfaces the server binds for LDAP and LDAPS.

dsconf <instance> config get nsslapd-listenhost nsslapd-securelistenhost

Remediation

Bind the secure listener to a specific management IP and restart.

dsconf <instance> config replace nsslapd-securelistenhost=<bind_ip>
dsctl <instance> restart

References

Implementation Notes

The chosen IP address must be present and configured on a host interface before restarting the server; if the address is absent at startup, 389DS will fail to bind and the instance will not start. Changing the listen host requires a full server restart to take effect. When managing both plain LDAP and LDAPS traffic separately, set nsslapd-listenhost in addition to nsslapd-securelistenhost as needed.