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๐Ÿ›ก๏ธ Azure Network Security Group allows public UDP access๐ŸŸข

  • Contextual name: ๐Ÿ›ก๏ธ Security Group allows public UDP access๐ŸŸข
  • ID: /ce/ca/azure/virtual-network/security-group-allows-unrestricted-udp-traffic
  • Tags:
  • Policy Type: COMPLIANCE_POLICY
  • Policy Categories: SECURITY

Statsโ€‹

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Logicโ€‹

Similar Policiesโ€‹

  • Internal: dec-x-e43fd12e

Similar Internal Rulesโ€‹

RulePoliciesFlags
โœ‰๏ธ dec-x-e43fd12e3

Descriptionโ€‹

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Descriptionโ€‹

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.

Rationaleโ€‹

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.

Auditโ€‹

This policy flags an Azure Network Security Group as INCOMPLIANT if it contains at least one Inbound Security Rule that meets all of the following conditions:

  • Direction is Inbound.
  • Access is Allow.
  • Protocol is Udp.
  • Source Address Prefix is either Internet, * 0.0.0.0, /0, or Any.

... see more

Remediationโ€‹

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Remediationโ€‹

Modify or Remove Insecure NSG Ruleโ€‹

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 CLIโ€‹

  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.yamlโ€‹

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Linked Framework Sectionsโ€‹

SectionSub SectionsInternal RulesPoliciesFlagsCompliance
๐Ÿ’ผ APRA CPG 234 โ†’ ๐Ÿ’ผ 36f network design โ€” to ensure authorised network traffic flows and to reduce the impact of security compromises;76107no data
๐Ÿ’ผ APRA CPG 234 โ†’ ๐Ÿ’ผ 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
๐Ÿ’ผ CIS Azure v1.3.0 โ†’ ๐Ÿ’ผ 6.6 Ensure that UDP Services are restricted from the Internet - Level 1 (Automated)๐Ÿ”ด13๐Ÿ”ด x1no data
๐Ÿ’ผ CIS Azure v1.4.0 โ†’ ๐Ÿ’ผ 6.6 Ensure that UDP Services are restricted from the Internet - Level 1 (Automated)๐Ÿ”ด13๐Ÿ”ด x1no data
๐Ÿ’ผ CIS Azure v1.5.0 โ†’ ๐Ÿ’ผ 6.3 Ensure that UDP access from the Internet is evaluated and restricted - Level 1 (Automated)๐Ÿ”ด13๐Ÿ”ด x1no data
๐Ÿ’ผ CIS Azure v2.0.0 โ†’ ๐Ÿ’ผ 6.3 Ensure that UDP access from the Internet is evaluated and restricted - Level 1 (Automated)๐Ÿ”ด13๐Ÿ”ด x1no data
๐Ÿ’ผ CIS Azure v2.1.0 โ†’ ๐Ÿ’ผ 6.3 Ensure that UDP access from the Internet is evaluated and restricted - Level 1 (Automated)๐Ÿ”ด13๐Ÿ”ด x1no data
๐Ÿ’ผ CIS Azure v5.0.0 โ†’ ๐Ÿ’ผ 7.3 Ensure that UDP access from the Internet is evaluated and restricted (Automated)1no data
๐Ÿ’ผ CIS Azure v6.0.0 โ†’ ๐Ÿ’ผ 7.3 Ensure that UDP Port Access from the Internet is Evaluated and Restricted (Automated)1no data
๐Ÿ’ผ Cloudaware Framework โ†’ ๐Ÿ’ผ Network Exposure137no data
๐Ÿ’ผ FedRAMP High Security Controls โ†’ ๐Ÿ’ผ AC-3 Access Enforcement (L)(M)(H)49103no data
๐Ÿ’ผ FedRAMP High Security Controls โ†’ ๐Ÿ’ผ AC-4(21) Physical or Logical Separation of Information Flows (M)(H)18141no data
๐Ÿ’ผ FedRAMP High Security Controls โ†’ ๐Ÿ’ผ CM-7 Least Functionality (L)(M)(H)32545no data
๐Ÿ’ผ FedRAMP High Security Controls โ†’ ๐Ÿ’ผ SC-7(5) Deny by Default โ€” Allow by Exception (M)(H)34no data
๐Ÿ’ผ FedRAMP Low Security Controls โ†’ ๐Ÿ’ผ AC-3 Access Enforcement (L)(M)(H)103no data
๐Ÿ’ผ FedRAMP Low Security Controls โ†’ ๐Ÿ’ผ CM-7 Least Functionality (L)(M)(H)36no data
๐Ÿ’ผ FedRAMP Moderate Security Controls โ†’ ๐Ÿ’ผ AC-3 Access Enforcement (L)(M)(H)103no data
๐Ÿ’ผ FedRAMP Moderate Security Controls โ†’ ๐Ÿ’ผ AC-4(21) Physical or Logical Separation of Information Flows (M)(H)141no data
๐Ÿ’ผ FedRAMP Moderate Security Controls โ†’ ๐Ÿ’ผ CM-7 Least Functionality (L)(M)(H)345no data
๐Ÿ’ผ FedRAMP Moderate Security Controls โ†’ ๐Ÿ’ผ SC-7(5) Deny by Default โ€” Allow by Exception (M)(H)34no data
๐Ÿ’ผ ISO/IEC 27001:2013 โ†’ ๐Ÿ’ผ A.9.4.1 Information access restriction4992no data
๐Ÿ’ผ ISO/IEC 27001:2022 โ†’ ๐Ÿ’ผ 6.7 Remote working518no data
๐Ÿ’ผ ISO/IEC 27001:2022 โ†’ ๐Ÿ’ผ 8.1 User end point devices1431no data
๐Ÿ’ผ ISO/IEC 27001:2022 โ†’ ๐Ÿ’ผ 8.16 Monitoring activities519no data
๐Ÿ’ผ ISO/IEC 27001:2022 โ†’ ๐Ÿ’ผ 8.22 Segregation of networks518no data
๐Ÿ’ผ NIST CSF v1.1 โ†’ ๐Ÿ’ผ PR.AC-4: Access permissions and authorizations are managed, incorporating the principles of least privilege and separation of duties48127no data
๐Ÿ’ผ NIST CSF v1.1 โ†’ ๐Ÿ’ผ PR.DS-5: Protections against data leaks are implemented89152no data
๐Ÿ’ผ NIST CSF v1.1 โ†’ ๐Ÿ’ผ 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
๐Ÿ’ผ NIST CSF v2.0 โ†’ ๐Ÿ’ผ 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
๐Ÿ’ผ NIST CSF v2.0 โ†’ ๐Ÿ’ผ PR.DS-01: The confidentiality, integrity, and availability of data-at-rest are protected248no data
๐Ÿ’ผ NIST CSF v2.0 โ†’ ๐Ÿ’ผ PR.DS-02: The confidentiality, integrity, and availability of data-in-transit are protected219no data
๐Ÿ’ผ NIST CSF v2.0 โ†’ ๐Ÿ’ผ PR.DS-10: The confidentiality, integrity, and availability of data-in-use are protected249no data
๐Ÿ’ผ NIST SP 800-53 Revision 5 โ†’ ๐Ÿ’ผ AC-4(21) Information Flow Enforcement _ Physical or Logical Separation of Information Flows83141no data
๐Ÿ’ผ NIST SP 800-53 Revision 5 โ†’ ๐Ÿ’ผ SC-7(5) Boundary Protection _ Deny by Default โ€” Allow by Exception1134no data
๐Ÿ’ผ PCI DSS v3.2.1 โ†’ ๐Ÿ’ผ 1.1 Establish and implement firewall and router configuration standards71110no data
๐Ÿ’ผ PCI DSS v3.2.1 โ†’ ๐Ÿ’ผ 1.3 Prohibit direct public access between the Internet and any system component in the cardholder data environment.712113no data
๐Ÿ’ผ PCI DSS v3.2.1 โ†’ ๐Ÿ’ผ 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
๐Ÿ’ผ PCI DSS v3.2.1 โ†’ ๐Ÿ’ผ 1.3.2 Limit inbound Internet traffic to IP addresses within the DMZ.100no data
๐Ÿ’ผ PCI DSS v3.2.1 โ†’ ๐Ÿ’ผ 1.3.5 Permit only โ€œestablishedโ€ connections into the network.100no data
๐Ÿ’ผ PCI DSS v4.0.1 โ†’ ๐Ÿ’ผ 1.2.1 Configuration standards for NSC rulesets are defined, implemented, maintained.105no data
๐Ÿ’ผ PCI DSS v4.0.1 โ†’ ๐Ÿ’ผ 1.4.1 NSCs are implemented between trusted and untrusted networks.90no data
๐Ÿ’ผ PCI DSS v4.0.1 โ†’ ๐Ÿ’ผ 1.4.2 Inbound traffic from untrusted networks to trusted networks is restricted.100no data
๐Ÿ’ผ PCI DSS v4.0 โ†’ ๐Ÿ’ผ 1.2.1 Configuration standards for NSC rulesets are defined, implemented, maintained.62105no data
๐Ÿ’ผ PCI DSS v4.0 โ†’ ๐Ÿ’ผ 1.4.1 NSCs are implemented between trusted and untrusted networks.3190no data
๐Ÿ’ผ PCI DSS v4.0 โ†’ ๐Ÿ’ผ 1.4.2 Inbound traffic from untrusted networks to trusted networks is restricted.31100no data
๐Ÿ’ผ SOC 2 โ†’ ๐Ÿ’ผ CC6.6-1 Restricts Access2162no data
๐Ÿ’ผ UK Cyber Essentials โ†’ ๐Ÿ’ผ 1.2 Prevent access to the administrative interface from the internet85119no data