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🛡️ Google GCE Network allows unrestricted traffic to all ports🟢

Stats​

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Logic​

Similar Policies​

  • Internal: dec-x-cd1c9f22

Similar Internal Rules​

RulePoliciesFlags
✉️ dec-x-cd1c9f221

Description​

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Description​

This policy identifies Google GCE Networks that have Firewall Rules allowing unrestricted incoming traffic (0.0.0.0/0) from the internet to all ports within a VPC Network.

In GCP, Firewall Rules are defined at the VPC Network level. Each rule either allows or denies traffic based on its configuration. These configurations specify the type of traffic (e.g., protocols and ports) and the source or destination (e.g., IP addresses, subnets, and instances).

Rationale​

Allowing unrestricted access to all ports across a network drastically increases the attack surface of every resource within that environment. Such a configuration can unintentionally expose internal services to reconnaissance, brute-force attempts, and other malicious activity originating from the public internet. To maintain a strong security posture, firewall rules should restrict access to only required ports and trusted IP ranges.

Impact​

External connections to the affected VPC(s) from untrusted sources may be blocked. If legitimate business needs require remote access, trusted source IP addresses should be explicitly defined in firewall rules to whitelist access only to the specific ports that are necessary for operation.

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Remediation​

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Remediation​

From Google Cloud Console​

  1. Go to VPC Network.
  2. Go to the Firewall Rules.
  3. Click the Firewall Rule to be modified.
  4. Click Edit.
  5. Modify Source IP ranges to specific IP ranges.
  6. Click Save.

From Google Cloud CLI​

  1. Identify Firewall Rules Allowing Public Access

    gcloud compute networks get-effective-firewalls default \
        --format="table(NAME, DIRECTION, {{ip-ranges}})" \
        --filter="{{ip-ranges}}:0.0.0.0/0 AND DIRECTION:INGRESS"

  2. Restrict the Source Range

    Once you have identified the firewall rules, update each one to restrict access to trusted CIDR ranges:

    gcloud compute firewall-rules update {{firewall-rule-name}} \
        --allow={{allowed-protocols}} \
        --source-ranges={{cidr-range1}},{{cidr-range2}}

policy.yaml​

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Linked Framework Sections​

SectionSub SectionsInternal RulesPoliciesFlagsCompliance
💼 APRA CPG 234 → 💼 36c deployment and environment management —development, test and production environments are appropriately segregated and enforce segregation of duties;711no data
💼 Cloudaware Framework → 💼 Network Exposure137no data
💼 FedRAMP High Security Controls → 💼 AC-4(21) Physical or Logical Separation of Information Flows (M)(H)18141no data
💼 FedRAMP Moderate Security Controls → 💼 AC-4(21) Physical or Logical Separation of Information Flows (M)(H)141no data
💼 ISO/IEC 27001:2013 → 💼 A.9.1.2 Access to networks and network services2767no data
💼 NIST CSF v1.1 → 💼 PR.AC-4: Access permissions and authorizations are managed, incorporating the principles of least privilege and separation of duties48127no data
💼 NIST CSF v1.1 → 💼 PR.AC-7: Users, devices, and other assets are authenticated (e.g., single-factor, multi-factor) commensurate with the risk of the transaction (e.g., individuals' security and privacy risks and other organizational risks)2428no data
💼 NIST CSF v1.1 → 💼 PR.DS-5: Protections against data leaks are implemented89152no data
💼 NIST CSF v1.1 → 💼 PR.PT-3: The principle of least functionality is incorporated by configuring systems to provide only essential capabilities3179no data
💼 NIST CSF v2.0 → 💼 PR.AA-03: Users, services, and hardware are authenticated102no data
💼 NIST CSF v2.0 → 💼 PR.AA-05: Access permissions, entitlements, and authorizations are defined in a policy, managed, enforced, and reviewed, and incorporate the principles of least privilege and separation of duties199no data
💼 NIST CSF v2.0 → 💼 PR.DS-01: The confidentiality, integrity, and availability of data-at-rest are protected248no data
💼 NIST CSF v2.0 → 💼 PR.DS-02: The confidentiality, integrity, and availability of data-in-transit are protected219no data
💼 NIST CSF v2.0 → 💼 PR.DS-10: The confidentiality, integrity, and availability of data-in-use are protected249no data
💼 NIST SP 800-53 Revision 5 → 💼 AC-4(21) Information Flow Enforcement _ Physical or Logical Separation of Information Flows83141no data
💼 PCI DSS v3.2.1 → 💼 1.1 Establish and implement firewall and router configuration standards71110no data
💼 PCI DSS v3.2.1 → 💼 1.1.6 Documentation of business justification and approval for use of all services, protocols, and ports allowed, including documentation of security features implemented for those protocols considered to be insecure.195no data
💼 PCI DSS v4.0.1 → 💼 1.2.1 Configuration standards for NSC rulesets are defined, implemented, maintained.105no data
💼 PCI DSS v4.0.1 → 💼 1.2.5 All services, protocols, and ports allowed are identified, approved, and have a defined business need.95no data
💼 PCI DSS v4.0.1 → 💼 1.2.6 Security features are defined and implemented for all services, protocols, and ports that are in use and considered to be insecure, such that the risk is mitigated.95no data
💼 PCI DSS v4.0 → 💼 1.2.1 Configuration standards for NSC rulesets are defined, implemented, maintained.62105no data
💼 PCI DSS v4.0 → 💼 1.2.5 All services, protocols, and ports allowed are identified, approved, and have a defined business need.4795no data
💼 PCI DSS v4.0 → 💼 1.2.6 Security features are defined and implemented for all services, protocols, and ports that are in use and considered to be insecure, such that the risk is mitigated.2195no data
💼 UK Cyber Essentials → 💼 1.2 Prevent access to the administrative interface from the internet85119no data