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πŸ›‘οΈ Azure VM Scale Set Instance allows public UDP access🟒

  • Contextual name: πŸ›‘οΈ Instance allows public UDP access🟒
  • ID: /ce/ca/azure/vm-scale-set/instance-allows-unrestricted-udp-traffic
  • Tags:
  • Policy Type: COMPLIANCE_POLICY
  • Policy Categories: SECURITY

Stats​

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Logic​

Similar Policies​

  • Internal: dec-x-e43fd12e

Similar Internal Rules​

RulePoliciesFlags
βœ‰οΈ dec-x-e43fd12e3

Description​

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Description​

Network security groups should be periodically evaluated for port misconfigurations. Where certain ports and protocols may be exposed to the Internet, they should be evaluated for necessity and restricted wherever they are not explicitly required.

Rationale​

The potential security problem with broadly exposing UDP services over the Internet is that attackers can use DDoS amplification techniques to reflect spoofed UDP traffic from Azure Virtual Machines. The most common types of these attacks use exposed DNS, NTP, SSDP, SNMP, CLDAP and other UDP-based services as amplification sources for disrupting services of other machines on the Azure Virtual Network or even attack networked devices outside of Azure.

Audit​

This policy flags an Azure VM Scale Set Instance as INCOMPLIANT if it is associated with a Network Interface that is connected to an NSG containing at least one Inbound Security Rule that meets all of the following conditions:

  • Direction is Inbound.
  • Access is Allow.

... see more

Remediation​

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Remediation​

Modify or Remove Insecure NSG Rule​

Review the security rules associated with the relevant Network Security Group (NSG) and determine whether they are required. Take appropriate action based on necessity and scope:

  • If the rule is not required: Remove the rule entirely.

  • If the rule is required but overly permissive: Update the rule to narrowly scope access, restricting the source IP range to only what is strictly necessary.

Azure CLI​

  1. Delete the rule:

    az network nsg rule delete \
      --resource-group {{resource-group-name}} \
      --nsg-name {{nsg-name}} \
      --name {{rule-name}}

  2. Restrict the rule:

    az network nsg rule update \
        --resource-group {{resource-group-name}} \
        --nsg-name {{nsg-name}} \
        --name {{rule-name}} \
        --source-address-prefixes {{trusted-cidr}}

    Replace placeholders with the appropriate values. Use space-separated values for multiple source prefixes or destination ports (e.g., --source-address-prefixes "1.2.3.4/32 5.6.7.8/32").

... see more

policy.yaml​

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Linked Framework Sections​

SectionSub SectionsInternal RulesPoliciesFlagsCompliance
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;76107no data
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.83115no data
πŸ’Ό CIS Azure v1.3.0 β†’ πŸ’Ό 6.6 Ensure that UDP Services are restricted from the Internet - Level 1 (Automated)πŸ”΄13πŸ”΄ x1no data
πŸ’Ό CIS Azure v1.4.0 β†’ πŸ’Ό 6.6 Ensure that UDP Services are restricted from the Internet - Level 1 (Automated)πŸ”΄13πŸ”΄ x1no data
πŸ’Ό CIS Azure v1.5.0 β†’ πŸ’Ό 6.3 Ensure that UDP access from the Internet is evaluated and restricted - Level 1 (Automated)πŸ”΄13πŸ”΄ x1no data
πŸ’Ό CIS Azure v2.0.0 β†’ πŸ’Ό 6.3 Ensure that UDP access from the Internet is evaluated and restricted - Level 1 (Automated)πŸ”΄13πŸ”΄ x1no data
πŸ’Ό CIS Azure v2.1.0 β†’ πŸ’Ό 6.3 Ensure that UDP access from the Internet is evaluated and restricted - Level 1 (Automated)πŸ”΄13πŸ”΄ x1no data
πŸ’Ό Cloudaware Framework β†’ πŸ’Ό Network Exposure137no data
πŸ’Ό FedRAMP High Security Controls β†’ πŸ’Ό AC-3 Access Enforcement (L)(M)(H)49103no data
πŸ’Ό FedRAMP High Security Controls β†’ πŸ’Ό AC-4(21) Physical or Logical Separation of Information Flows (M)(H)18141no data
πŸ’Ό FedRAMP High Security Controls β†’ πŸ’Ό CM-7 Least Functionality (L)(M)(H)32545no data
πŸ’Ό FedRAMP High Security Controls β†’ πŸ’Ό SC-7(5) Deny by Default β€” Allow by Exception (M)(H)34no data
πŸ’Ό FedRAMP Low Security Controls β†’ πŸ’Ό AC-3 Access Enforcement (L)(M)(H)103no data
πŸ’Ό FedRAMP Low Security Controls β†’ πŸ’Ό CM-7 Least Functionality (L)(M)(H)36no data
πŸ’Ό FedRAMP Moderate Security Controls β†’ πŸ’Ό AC-3 Access Enforcement (L)(M)(H)103no data
πŸ’Ό FedRAMP Moderate Security Controls β†’ πŸ’Ό AC-4(21) Physical or Logical Separation of Information Flows (M)(H)141no data
πŸ’Ό FedRAMP Moderate Security Controls β†’ πŸ’Ό CM-7 Least Functionality (L)(M)(H)345no data
πŸ’Ό FedRAMP Moderate Security Controls β†’ πŸ’Ό SC-7(5) Deny by Default β€” Allow by Exception (M)(H)34no data
πŸ’Ό ISO/IEC 27001:2013 β†’ πŸ’Ό A.9.4.1 Information access restriction4992no data
πŸ’Ό ISO/IEC 27001:2022 β†’ πŸ’Ό 6.7 Remote working518no data
πŸ’Ό ISO/IEC 27001:2022 β†’ πŸ’Ό 8.1 User end point devices1431no data
πŸ’Ό ISO/IEC 27001:2022 β†’ πŸ’Ό 8.16 Monitoring activities519no data
πŸ’Ό ISO/IEC 27001:2022 β†’ πŸ’Ό 8.22 Segregation of networks518no data
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 duties48127no data
πŸ’Ό NIST CSF v1.1 β†’ πŸ’Ό PR.DS-5: Protections against data leaks are implemented89152no data
πŸ’Ό NIST CSF v1.1 β†’ πŸ’Ό PR.IP-1: A baseline configuration of information technology/industrial control systems is created and maintained incorporating security principles (e.g. concept of least functionality)533no data
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 duties199no data
πŸ’Ό NIST CSF v2.0 β†’ πŸ’Ό PR.DS-01: The confidentiality, integrity, and availability of data-at-rest are protected248no data
πŸ’Ό NIST CSF v2.0 β†’ πŸ’Ό PR.DS-02: The confidentiality, integrity, and availability of data-in-transit are protected219no data
πŸ’Ό NIST CSF v2.0 β†’ πŸ’Ό PR.DS-10: The confidentiality, integrity, and availability of data-in-use are protected249no data
πŸ’Ό NIST SP 800-53 Revision 5 β†’ πŸ’Ό AC-4(21) Information Flow Enforcement _ Physical or Logical Separation of Information Flows83141no data
πŸ’Ό NIST SP 800-53 Revision 5 β†’ πŸ’Ό SC-7(5) Boundary Protection _ Deny by Default β€” Allow by Exception1134no data
πŸ’Ό PCI DSS v3.2.1 β†’ πŸ’Ό 1.1 Establish and implement firewall and router configuration standards71110no data
πŸ’Ό PCI DSS v3.2.1 β†’ πŸ’Ό 1.3 Prohibit direct public access between the Internet and any system component in the cardholder data environment.712113no data
πŸ’Ό PCI DSS v3.2.1 β†’ πŸ’Ό 1.3.1 Implement a DMZ to limit inbound traffic to only system components that provide authorized publicly accessible services, protocols, and ports.10100no data
πŸ’Ό PCI DSS v3.2.1 β†’ πŸ’Ό 1.3.2 Limit inbound Internet traffic to IP addresses within the DMZ.100no data
πŸ’Ό PCI DSS v3.2.1 β†’ πŸ’Ό 1.3.5 Permit only β€œestablished” connections into the network.100no data
πŸ’Ό PCI DSS v4.0.1 β†’ πŸ’Ό 1.2.1 Configuration standards for NSC rulesets are defined, implemented, maintained.105no data
πŸ’Ό PCI DSS v4.0.1 β†’ πŸ’Ό 1.4.1 NSCs are implemented between trusted and untrusted networks.90no data
πŸ’Ό PCI DSS v4.0.1 β†’ πŸ’Ό 1.4.2 Inbound traffic from untrusted networks to trusted networks is restricted.100no data
πŸ’Ό PCI DSS v4.0 β†’ πŸ’Ό 1.2.1 Configuration standards for NSC rulesets are defined, implemented, maintained.62105no data
πŸ’Ό PCI DSS v4.0 β†’ πŸ’Ό 1.4.1 NSCs are implemented between trusted and untrusted networks.3190no data
πŸ’Ό PCI DSS v4.0 β†’ πŸ’Ό 1.4.2 Inbound traffic from untrusted networks to trusted networks is restricted.31100no data
πŸ’Ό SOC 2 β†’ πŸ’Ό CC6.6-1 Restricts Access2162no data
πŸ’Ό UK Cyber Essentials β†’ πŸ’Ό 1.2 Prevent access to the administrative interface from the internet85119no data