The organization network must be segmented.
CIS Controls. 12.3 Deny Communications With Known Malicious IP Addresses. Deny communications with known malicious or unused Internet IP addresses and limit access only to trusted and necessary IP address ranges at each of the organization’s network boundaries.
CWE-923: Improper Restriction of Communication Channel to Intended Endpoints. The software establishes a communication channel to an endpoint for privileged or protected operations, but it does not properly ensure that it is communicating with the correct endpoint.
ISO 27001:2013. Annex A - 13.1.3 Separate information systems, users and information services groups in the network.
OWASP Top 10 A6:2017-Security Misconfiguration. Security misconfiguration is the most commonly seen issue. This is commonly a result of insecure default configurations, incomplete or ad hoc configurations, open cloud storage, misconfigured HTTP headers, and verbose error messages.
OWASP-ASVS v4.0.1 V6.4 Secret Management.(6.4.1) Verify the segregation of components of differing trust levels through well-defined security controls, firewall rules, API gateways, reverse proxies, cloud-based security groups, or similar mechanisms.
PCI DSS v3.2.1 - Requirement 1.2.1 Restrict inbound and outbound traffic to that which is necessary for the cardholder data environment, and specifically deny all other traffic.
PCI DSS v3.2.1 - Requirement 1.2.3 Install perimeter firewalls between all wireless networks and the cardholder data environment. Configure these firewalls to deny or, if traffic is necessary for business purposes, permit only authorized traffic.
PCI DSS v3.2.1 - Requirement 1.3.1 Implement a DMZ to limit inbound traffic to only system components that provide authorized publicly accessible services, protocols, and ports.
PCI DSS v3.2.1 - Requirement 1.3.2 Limit inbound Internet traffic to IP addresses within the DMZ.
PCI DSS v3.2.1 - Requirement 1.3.3 Implement anti-spoofing measures to detect and block forged source IP addresses from entering the network.
PCI DSS v3.2.1 - Requirement 1.3.4 Do not allow unauthorized outbound traffic from the cardholder data environment to the Internet.
PCI DSS v3.2.1 - Requirement 1.3.6 Place system components that store cardholder data (such as a database) in an internal network zone, segregated from the DMZ and other untrusted networks.