STIGQter: STIG Summary: Application Layer Gateway Security Requirements Guide Version: 2 Release: 4 Benchmark Date: 01 Jul 2026:

The ALG that provides intermediary services for SMTP must inspect inbound and outbound SMTP and Extended SMTP communications traffic for protocol compliance and protocol anomalies.

DISA Rule

SV-205048r396519_rule

Vulnerability Number

V-205048

Group Title

SRG-NET-000512

Rule Version

SRG-NET-000512-ALG-000064

Severity

CAT II

CCI(s)

• CCI-000366 - Implement the security configuration settings.
• CCI-001125 - Enforce adherence to protocol formats.

Weight

10

Fix Recommendation

If the ALG provides intermediary/proxy services SMTP communications traffic, configure the ALG to inspect inbound and outbound SMTP and Extended SMTP communications traffic for protocol compliance and protocol anomalies.

Check Contents

If the ALG does not provide intermediary/proxy services for SMTP communications traffic, this is not applicable.

Verify the ALG inspects inbound and outbound SMTP and Extended SMTP communications traffic for protocol compliance and protocol anomalies.

If the ALG does not inspect inbound and outbound SMTP and Extended SMTP communications traffic for protocol compliance and protocol anomalies, this is a finding.

Vulnerability Number

V-205048

Documentable

False

Rule Version

SRG-NET-000512-ALG-000064

Severity Override Guidance

If the ALG does not provide intermediary/proxy services for SMTP communications traffic, this is not applicable.

Verify the ALG inspects inbound and outbound SMTP and Extended SMTP communications traffic for protocol compliance and protocol anomalies.

If the ALG does not inspect inbound and outbound SMTP and Extended SMTP communications traffic for protocol compliance and protocol anomalies, this is a finding.

Check Content Reference

M

Target Key

2904