STIGQter: STIG Summary: Red Hat Enterprise Linux 10 Security Technical Implementation Guide Version: 1 Release: 2 Benchmark Date: 01 Jul 2026:

RHEL 10 must be configured to prevent unrestricted mail relaying.

DISA Rule

SV-280999r1165352_rule

Vulnerability Number

V-280999

Group Title

SRG-OS-000095-GPOS-00049

Rule Version

RHEL-10-200692

Severity

CAT II

CCI(s)

• CCI-000381 - Configure the system to provide only organization-defined mission essential capabilities.

Weight

10

Fix Recommendation

Configure RHEL 10 so that the postfix configuration file restricts client connections to the local network with the following command:

$ sudo postconf -e 'smtpd_client_restrictions = permit_mynetworks,reject'

Check Contents

Note: If postfix is not installed, this is not applicable.

Verify RHEL 10 is configured to prevent unrestricted mail relaying with the following command:

$ postconf -n smtpd_client_restrictions
smtpd_client_restrictions = permit_mynetworks,reject

If the "smtpd_client_restrictions" parameter contains any entries other than "permit_mynetworks" and "reject", and the additional entries have not been documented with the information system security officer, this is a finding.

Vulnerability Number

V-280999

Documentable

False

Rule Version

RHEL-10-200692

Severity Override Guidance

Note: If postfix is not installed, this is not applicable.

Verify RHEL 10 is configured to prevent unrestricted mail relaying with the following command:

$ postconf -n smtpd_client_restrictions
smtpd_client_restrictions = permit_mynetworks,reject

If the "smtpd_client_restrictions" parameter contains any entries other than "permit_mynetworks" and "reject", and the additional entries have not been documented with the information system security officer, this is a finding.

Check Content Reference

M

Target Key

5733