github.com/khulnasoft-lab/defsec@v1.0.5-0.20230827010352-5e9f46893d95/rules/cloud/policies/azure/network/no_public_ingress.go (about)

     1  package network
     2  
     3  import (
     4  	"github.com/khulnasoft-lab/defsec/internal/cidr"
     5  	"github.com/khulnasoft-lab/defsec/internal/rules"
     6  	"github.com/khulnasoft-lab/defsec/pkg/providers"
     7  	"github.com/khulnasoft-lab/defsec/pkg/scan"
     8  	"github.com/khulnasoft-lab/defsec/pkg/severity"
     9  	"github.com/khulnasoft-lab/defsec/pkg/state"
    10  )
    11  
    12  var CheckNoPublicIngress = rules.Register(
    13  	scan.Rule{
    14  		AVDID:      "AVD-AZU-0047",
    15  		Provider:   providers.AzureProvider,
    16  		Service:    "network",
    17  		ShortCode:  "no-public-ingress",
    18  		Summary:    "An inbound network security rule allows traffic from /0.",
    19  		Impact:     "The port is exposed for ingress from the internet",
    20  		Resolution: "Set a more restrictive cidr range",
    21  		Explanation: `Network security rules should not use very broad subnets.
    22  
    23  Where possible, segments should be broken into smaller subnets.`,
    24  		Links: []string{
    25  			"https://docs.microsoft.com/en-us/azure/security/fundamentals/network-best-practices",
    26  		},
    27  		Terraform: &scan.EngineMetadata{
    28  			GoodExamples:        terraformNoPublicIngressGoodExamples,
    29  			BadExamples:         terraformNoPublicIngressBadExamples,
    30  			Links:               terraformNoPublicIngressLinks,
    31  			RemediationMarkdown: terraformNoPublicIngressRemediationMarkdown,
    32  		},
    33  		Severity: severity.Critical,
    34  	},
    35  	func(s *state.State) (results scan.Results) {
    36  		for _, group := range s.Azure.Network.SecurityGroups {
    37  			var failed bool
    38  			for _, rule := range group.Rules {
    39  				if rule.Outbound.IsTrue() || rule.Allow.IsFalse() {
    40  					continue
    41  				}
    42  				for _, ip := range rule.SourceAddresses {
    43  					// single public IPs acceptable to allow for well known IP addresses to be used
    44  					if cidr.IsPublic(ip.Value()) && cidr.CountAddresses(ip.Value()) > 1 {
    45  						failed = true
    46  						results.Add(
    47  							"Security group rule allows ingress from public internet.",
    48  							ip,
    49  						)
    50  					}
    51  				}
    52  			}
    53  			if !failed {
    54  				results.AddPassed(&group)
    55  			}
    56  		}
    57  		return
    58  	},
    59  )