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πŸ“ AWS EC2 Security Group allows unrestricted RPC traffic 🟒

  • Contextual name: πŸ“ Security Group allows unrestricted RPC traffic 🟒
  • ID: /ce/ca/aws/ec2/security-group-allows-unrestricted-rpc-traffic
  • Located in: πŸ“ AWS EC2

Flags​

Our Metadata​

  • Policy Type: COMPLIANCE_POLICY
  • Policy Category:
    • SECURITY

Similar Policies​

Similar Internal Rules​

RulePoliciesFlags
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Logic​

Description​

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Description​

Restrict inbound RPC traffic in AWS EC2 security groups to enhance network security and prevent unauthorized communication. RPC traffic, typically associated with port 135, facilitates inter-process communication between distributed systems. However, unrestricted access to this port poses significant security risks, including unauthorized access or exploitation of vulnerabilities.

Rational​

RPC traffic is commonly exploited by attackers to gain unauthorized access to systems or execute malicious actions remotely. By restricting RPC traffic in security groups, organizations can mitigate risks such as unauthorized data access, lateral movement within networks, and exploitation of protocol vulnerabilities. Unchecked RPC traffic can also facilitate the spread of malware within a network. Limiting access to trusted IP ranges reduces the overall attack surface, thereby strengthening the security of the associated EC2 instances.

Impact​

Restricting RPC traffic requires evaluating dependent applications to ensure they're functionality is not disrupted.

... see more

Remediation​

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Remediation​

From Command Line​

  1. Run the following command to remove or modify the unrestricted rule for RPC access:
aws ec2 revoke-security-group-ingress \
--region {{region-name}} \
--group-id {{security-group-id}} \
--protocol {{protocol}} \
--port 135 \
--cidr {{0.0.0.0/0 or ::/0}}
  • Optionally, run the authorise-security-group-ingress command to create a new rule, specifying a trusted CIDR range instead of 0.0.0.0/0.

  1. Confirm the changes by describing the security group again and ensuring the unrestricted access rule has been removed or appropriately restricted:
aws ec2 describe-security-groups \
--region {{region-name}} \
--group-ids {{security-group-id}} \
--query 'SecurityGroups[*].IpPermissions[?FromPort==`135`].{CIDR:IpRanges[*].CidrIp,Port:FromPort}'
  1. Test applications dependent on RPC to ensure they are unaffected by the changes.

policy.yaml​

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Linked Framework Sections​

SectionSub SectionsInternal RulesPoliciesFlags
πŸ’Ό APRA CPG 234 β†’ πŸ’Ό 36f network design β€” to ensure authorised network traffic flows and to reduce the impact of security compromises;2930
πŸ’Ό APRA CPG 234 β†’ πŸ’Ό 45 An understanding of plausible worst case scenarios can help regulated entities identify and implement additional controls to prevent or reduce the impact of such scenarios. One example is malware that infects computers and encrypts data, both on the infected computer and any connected storage, including (corporate) networks and cloud storage. Such attacks reinforce the importance of protecting the backup environment in the event that the production environment is compromised. Common techniques to achieve this include network segmentation, highly restricted and segregated access controls and network traffic flow restrictions.3537
πŸ’Ό AWS Foundational Security Best Practices v1.0.0 β†’ πŸ’Ό [EC2.19] Security groups should not allow unrestricted access to ports with high risk10
πŸ’Ό Cloudaware Framework β†’ πŸ’Ό Threat Protection27
πŸ’Ό FedRAMP High Security Controls β†’ πŸ’Ό AC-3 Access Enforcement (L)(M)(H)3764
πŸ’Ό FedRAMP High Security Controls β†’ πŸ’Ό AC-4 Information Flow Enforcement (M)(H)23675
πŸ’Ό FedRAMP High Security Controls β†’ πŸ’Ό AC-4(21) Physical or Logical Separation of Information Flows (M)(H)1142
πŸ’Ό FedRAMP High Security Controls β†’ πŸ’Ό CM-2 Baseline Configuration (L)(M)(H)3124
πŸ’Ό FedRAMP High Security Controls β†’ πŸ’Ό CM-2(2) Automation Support for Accuracy and Currency (M)(H)14
πŸ’Ό FedRAMP High Security Controls β†’ πŸ’Ό CM-7 Least Functionality (L)(M)(H)31833
πŸ’Ό FedRAMP High Security Controls β†’ πŸ’Ό CM-7(1) Periodic Review (M)(H)1212
πŸ’Ό FedRAMP High Security Controls β†’ πŸ’Ό SC-7 Boundary Protection (L)(M)(H)10845
πŸ’Ό FedRAMP High Security Controls β†’ πŸ’Ό SC-7(4) External Telecommunications Services (M)(H)25
πŸ’Ό FedRAMP High Security Controls β†’ πŸ’Ό SC-7(5) Deny by Default β€” Allow by Exception (M)(H)18
πŸ’Ό FedRAMP High Security Controls β†’ πŸ’Ό SC-7(21) Isolation of System Components (H)19
πŸ’Ό FedRAMP Low Security Controls β†’ πŸ’Ό AC-3 Access Enforcement (L)(M)(H)64
πŸ’Ό FedRAMP Low Security Controls β†’ πŸ’Ό CM-2 Baseline Configuration (L)(M)(H)23
πŸ’Ό FedRAMP Low Security Controls β†’ πŸ’Ό CM-7 Least Functionality (L)(M)(H)29
πŸ’Ό FedRAMP Low Security Controls β†’ πŸ’Ό SC-7 Boundary Protection (L)(M)(H)30
πŸ’Ό FedRAMP Moderate Security Controls β†’ πŸ’Ό AC-3 Access Enforcement (L)(M)(H)64
πŸ’Ό FedRAMP Moderate Security Controls β†’ πŸ’Ό AC-4 Information Flow Enforcement (M)(H)160
πŸ’Ό FedRAMP Moderate Security Controls β†’ πŸ’Ό AC-4(21) Physical or Logical Separation of Information Flows (M)(H)42
πŸ’Ό FedRAMP Moderate Security Controls β†’ πŸ’Ό CM-2 Baseline Configuration (L)(M)(H)324
πŸ’Ό FedRAMP Moderate Security Controls β†’ πŸ’Ό CM-2(2) Automation Support for Accuracy and Currency (M)(H)14
πŸ’Ό FedRAMP Moderate Security Controls β†’ πŸ’Ό CM-7 Least Functionality (L)(M)(H)333
πŸ’Ό FedRAMP Moderate Security Controls β†’ πŸ’Ό CM-7(1) Periodic Review (M)(H)12
πŸ’Ό FedRAMP Moderate Security Controls β†’ πŸ’Ό SC-7 Boundary Protection (L)(M)(H)739
πŸ’Ό FedRAMP Moderate Security Controls β†’ πŸ’Ό SC-7(4) External Telecommunications Services (M)(H)25
πŸ’Ό FedRAMP Moderate Security Controls β†’ πŸ’Ό SC-7(5) Deny by Default β€” Allow by Exception (M)(H)18
πŸ’Ό ISO/IEC 27001:2013 β†’ πŸ’Ό A.9.1.2 Access to networks and network services1718
πŸ’Ό NIST CSF v1.1 β†’ πŸ’Ό PR.AC-4: Access permissions and authorizations are managed, incorporating the principles of least privilege and separation of duties1752
πŸ’Ό NIST CSF v1.1 β†’ πŸ’Ό PR.DS-5: Protections against data leaks are implemented4766
πŸ’Ό NIST CSF v1.1 β†’ πŸ’Ό PR.PT-3: The principle of least functionality is incorporated by configuring systems to provide only essential capabilities2130
πŸ’Ό NIST CSF v2.0 β†’ πŸ’Ό DE.CM-01: Networks and network services are monitored to find potentially adverse events115
πŸ’Ό NIST CSF v2.0 β†’ πŸ’Ό DE.CM-09: Computing hardware and software, runtime environments, and their data are monitored to find potentially adverse events134
πŸ’Ό NIST CSF v2.0 β†’ πŸ’Ό ID.AM-03: Representations of the organization's authorized network communication and internal and external network data flows are maintained45
πŸ’Ό NIST CSF v2.0 β†’ πŸ’Ό 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 duties88
πŸ’Ό NIST CSF v2.0 β†’ πŸ’Ό PR.DS-01: The confidentiality, integrity, and availability of data-at-rest are protected114
πŸ’Ό NIST CSF v2.0 β†’ πŸ’Ό PR.DS-02: The confidentiality, integrity, and availability of data-in-transit are protected94
πŸ’Ό NIST CSF v2.0 β†’ πŸ’Ό PR.DS-10: The confidentiality, integrity, and availability of data-in-use are protected108
πŸ’Ό NIST CSF v2.0 β†’ πŸ’Ό PR.IR-01: Networks and environments are protected from unauthorized logical access and usage66
πŸ’Ό NIST SP 800-53 Revision 5 β†’ πŸ’Ό AC-4 Information Flow Enforcement326885
πŸ’Ό NIST SP 800-53 Revision 5 β†’ πŸ’Ό AC-4(21) Information Flow Enforcement _ Physical or Logical Separation of Information Flows3742
πŸ’Ό NIST SP 800-53 Revision 5 β†’ πŸ’Ό CA-9(1) Internal System Connections _ Compliance Checks20
πŸ’Ό NIST SP 800-53 Revision 5 β†’ πŸ’Ό CM-2 Baseline Configuration723
πŸ’Ό NIST SP 800-53 Revision 5 β†’ πŸ’Ό CM-2(2) Baseline Configuration _ Automation Support for Accuracy and Currency14
πŸ’Ό NIST SP 800-53 Revision 5 β†’ πŸ’Ό CM-7 Least Functionality923
πŸ’Ό NIST SP 800-53 Revision 5 β†’ πŸ’Ό SC-7 Boundary Protection29447
πŸ’Ό NIST SP 800-53 Revision 5 β†’ πŸ’Ό SC-7(4) Boundary Protection _ External Telecommunications Services25
πŸ’Ό NIST SP 800-53 Revision 5 β†’ πŸ’Ό SC-7(5) Boundary Protection _ Deny by Default β€” Allow by Exception418
πŸ’Ό NIST SP 800-53 Revision 5 β†’ πŸ’Ό SC-7(11) Boundary Protection _ Restrict Incoming Communications Traffic19
πŸ’Ό NIST SP 800-53 Revision 5 β†’ πŸ’Ό SC-7(16) Boundary Protection _ Prevent Discovery of System Components20
πŸ’Ό NIST SP 800-53 Revision 5 β†’ πŸ’Ό SC-7(21) Boundary Protection _ Isolation of System Components19
πŸ’Ό PCI DSS v3.2.1 β†’ πŸ’Ό 1.1 Establish and implement firewall and router configuration standards7138
πŸ’Ό PCI DSS v3.2.1 β†’ πŸ’Ό 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.127
πŸ’Ό PCI DSS v3.2.1 β†’ πŸ’Ό 1.2.1 Restrict inbound and outbound traffic to that which is necessary for the cardholder data environment, and specifically deny all other traffic.1035
πŸ’Ό PCI DSS v3.2.1 β†’ πŸ’Ό 2.2.3 Implement additional security features for any required services, protocols, or daemons that are considered to be insecure.33
πŸ’Ό PCI DSS v3.2.1 β†’ πŸ’Ό 2.2.4 Configure system security parameters to prevent misuse.16
πŸ’Ό PCI DSS v4.0.1 β†’ πŸ’Ό 1.2.1 Configuration standards for NSC rulesets are defined, implemented, maintained.34
πŸ’Ό PCI DSS v4.0.1 β†’ πŸ’Ό 1.2.5 All services, protocols, and ports allowed are identified, approved, and have a defined business need.27
πŸ’Ό PCI DSS v4.0.1 β†’ πŸ’Ό 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.27
πŸ’Ό PCI DSS v4.0.1 β†’ πŸ’Ό 1.3.1 Inbound traffic to the CDE is restricted.35
πŸ’Ό PCI DSS v4.0.1 β†’ πŸ’Ό 1.3.2 Outbound traffic from the CDE is restricted.35
πŸ’Ό PCI DSS v4.0.1 β†’ πŸ’Ό 2.2.5 If any insecure services, protocols, or daemons are present, business justification is documented.3
πŸ’Ό PCI DSS v4.0.1 β†’ πŸ’Ό 2.2.6 System security parameters are configured to prevent misuse.16
πŸ’Ό PCI DSS v4.0 β†’ πŸ’Ό 1.2.1 Configuration standards for NSC rulesets are defined, implemented, maintained.2434
πŸ’Ό PCI DSS v4.0 β†’ πŸ’Ό 1.2.5 All services, protocols, and ports allowed are identified, approved, and have a defined business need.1527
πŸ’Ό PCI DSS v4.0 β†’ πŸ’Ό 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.627
πŸ’Ό PCI DSS v4.0 β†’ πŸ’Ό 1.3.1 Inbound traffic to the CDE is restricted.735
πŸ’Ό PCI DSS v4.0 β†’ πŸ’Ό 1.3.2 Outbound traffic from the CDE is restricted.35
πŸ’Ό PCI DSS v4.0 β†’ πŸ’Ό 2.2.5 If any insecure services, protocols, or daemons are present, business justification is documented.3
πŸ’Ό PCI DSS v4.0 β†’ πŸ’Ό 2.2.6 System security parameters are configured to prevent misuse.1216
πŸ’Ό SOC 2 β†’ πŸ’Ό CC6.1-7 Restricts Access to Information Assets1326
πŸ’Ό SOC 2 β†’ πŸ’Ό CC6.6-1 Restricts Access1619
πŸ’Ό UK Cyber Essentials β†’ πŸ’Ό 1.2 Prevent access to the administrative interface from the internet3638