Impair Defenses: Disable or Modify Cloud Firewall

Adversaries may disable or modify a firewall within a cloud environment to bypass controls that limit access to cloud resources. Cloud firewalls are separate from system firewalls that are described in Disable or Modify System Firewall.

Cloud environments typically utilize restrictive security groups and firewall rules that only allow network activity from trusted IP addresses via expected ports and protocols. An adversary may introduce new firewall rules or policies to allow access into a victim cloud environment. For example, an adversary may use a script or utility that creates new ingress rules in existing security groups to allow any TCP/IP connectivity.[1]

Modifying or disabling a cloud firewall may enable adversary C2 communications, lateral movement, and/or data exfiltration that would otherwise not be allowed.

ID: T1562.007
Sub-technique of:  T1562
Tactic: Defense Evasion
Platforms: AWS, Azure, GCP
Permissions Required: User
Data Sources: AWS CloudTrail logs, Azure activity logs, GCP audit logs, Stackdriver logs
Contributors: Expel
Version: 1.0
Created: 24 June 2020
Last Modified: 07 July 2020

Mitigations

Mitigation Description
Audit

Routinely check account role permissions to ensure only expected users and roles have permission to modify cloud firewalls.

User Account Management

Ensure least privilege principles are applied to Identity and Access Management (IAM) security policies.[1]

Detection

Monitor cloud logs for modification or creation of new security groups or firewall rules.

References