STIGUI
V-279222CAT II — Medium severitySV-279222r1170676_rule

The Edge SWG must fail securely in the event of an operational failure.

Rule version SYME-00-010200 · STIG v1 · 2026-08-25

Discussion

If a boundary protection device fails in an unsecure manner (open), information external to the boundary protection device may enter, or the device may permit unauthorized information release.

Secure failure ensures when a boundary control device fails, all traffic will be subsequently denied.

Fail secure is a condition achieved by employing information system mechanisms to ensure, in the event of operational failures of boundary protection devices at managed interfaces (e.g., routers, firewalls, guards, and application gateways residing on protected subnetworks commonly referred to as demilitarized zones), information systems do not enter into unsecure states where intended security properties no longer hold.

Check

1. Log in to the Integrated Secure Gateway (ISG) SSH CLI. 2. Enter "enable" and "configure terminal". 3. Enter "bridge view".

If the mode for the bridge in use does not state "fail-closed", this is a finding.

Fix

1. Log in to the Integrated Secure Gateway (ISG) SSH CLI. 2. Enter "enable" and "configure terminal". 3. Enter "bridge view". 4. Find the bridge in use for the Edge SWG, e.g., "passthru-2:0". 5. Enter "bridge edit passthru-2:0 mode fail-closed".

Identifiers

Group ID
V-279222
Group title
SRG-NET-000365-ALG-000123
Rule ID
SV-279222r1170676_rule
Check ID
C-83770r1170675_chk
Fix ID
F-83675r1170649_fix