Egress Filtering and Allow-Listing

What It Does

Constrain outbound destinations so command channels must use paths you inspect.

Observable indicator. Outbound connections resolve to an allow-listed destination or fail.

Where It Sits

A technique is chosen from inside a form and emplaced on one layer. Both are the catalog’s own declarations; the position is counted in catalog order.

• Form of maneuverM4 Obstacle / CanalizationForce the adversary onto ground you own and watch.
• Terrain layerT3 NetworksThe corridors. Key terrain: TIC 3.0 access points, segment boundaries, cloud VPC peering.
• Position in the form3 of 17M4 carries 17 cataloged techniques; this is the 3rd in catalog order.

Phases It Is Employed In

Employed in 2 of the campaign’s six phases. A phase named here means at least this technique is live in it — not that the form it belongs to is the main effort.

• Phase 0ShapeContinuous terrain preparation, zero-trust hardening, partnerships, threat intelligence.
• Phase IDeterVisible hardening, a deception grid, and a stated attribution posture.

Controls That Assess It

The controls the catalog names against this technique. They are what an assessor would test to establish that it is emplaced and working — the indicator above is what shows it is working, which is a different question.

• KT-5 Barrier SufficiencyKey Terrain and Decisive Points — To make the barriers on which negative reachability results depend into named, owned, monitored controls, so that the assurance KT-4 provides cannot be silently withdrawn.
• TM-5 Connection and Denied-Path RegisterTerrain Management — To record connectivity as three distinct states — permitted, denied, unknown — so that reachability conclusions rest on tested denials rather than on absence of evidence.

In MITRE D3FEND

What this technique is called in MITRE’s countermeasure ontology. The join runs technique-to-technique: D3FEND catalogs countermeasures, and the thing with a countermeasure’s shape here is the technique, not the control.

• D3-CF Content FilteringIsolate tactic
• D3-CFC Content Format ConversionIsolate tactic
• D3-OTF Outbound Traffic FilteringIsolate tactic

That a technique reaches a D3FEND countermeasure says the two describe the same defensive act. It does not say the countermeasure is deployed, configured, or working — that is an assessment finding about your estate, not a property of the framework.

Related Techniques

The catalog declares no relation for this entry, and no other entry names it — the inverse is derived here, so an incoming edge would show up even though this one never declared it. The techniques below share its assessment surface, which is the nearest adjacency the data supports.

Assessed Alongside

Not a declared relation: these are the techniques whose assessing controls overlap this one’s, ranked by how much of the two assessment surfaces coincide. Showing 6 of 22 that share at least one control.

• 2 shared controlsM4.02 East-West Deny by DefaultM4 Obstacle / Canalization · T3 Networks
  • KT-5
  • TM-5
• 2 shared controlsM4.11 Protocol and Port RestrictionM4 Obstacle / Canalization · T3 Networks
  • KT-5
  • TM-5
• 1 shared controlM2.01 Trust Zone ArchitectureM2 Defense in Depth · T3 Networks
  • TM-5
• 1 shared controlM2.04 Independent Control RedundancyM2 Defense in Depth · TX Cross-Cutting
  • KT-5
• 1 shared controlM2.10 Egress Data Loss PreventionM2 Defense in Depth · T5 Data
  • KT-5
• 1 shared controlM4.01 MicrosegmentationM4 Obstacle / Canalization · T3 Networks
  • KT-5