lambda

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Index

• Variables

Variables

var CheckEnableTracing = rules.Register(
	rules.Rule{
		AVDID:       "AVD-AWS-0066",
		Provider:    providers.AWSProvider,
		Service:     "lambda",
		ShortCode:   "enable-tracing",
		Summary:     "Lambda functions should have X-Ray tracing enabled",
		Impact:      "WIthout full tracing enabled it is difficult to trace the flow of logs",
		Resolution:  "Enable tracing",
		Explanation: `X-Ray tracing enables end-to-end debugging and analysis of all function activity. This will allow for identifying bottlenecks, slow downs and timeouts.`,
		Links: []string{
			"https://docs.aws.amazon.com/lambda/latest/dg/services-xray.html",
		},
		Terraform: &rules.EngineMetadata{
			GoodExamples:        terraformEnableTracingGoodExamples,
			BadExamples:         terraformEnableTracingBadExamples,
			Links:               terraformEnableTracingLinks,
			RemediationMarkdown: terraformEnableTracingRemediationMarkdown,
		},
		CloudFormation: &rules.EngineMetadata{
			GoodExamples:        cloudFormationEnableTracingGoodExamples,
			BadExamples:         cloudFormationEnableTracingBadExamples,
			Links:               cloudFormationEnableTracingLinks,
			RemediationMarkdown: cloudFormationEnableTracingRemediationMarkdown,
		},
		Severity: severity.Low,
	},
	func(s *state.State) (results rules.Results) {
		for _, function := range s.AWS.Lambda.Functions {
			if function.IsUnmanaged() {
				continue
			}
			if function.Tracing.Mode.NotEqualTo(lambda.TracingModeActive) && function.Tracing.Mode.NotEqualTo(lambda.TracingModePassThrough) {
				results.Add(
					"Function does not have tracing enabled.",
					function.Tracing.Mode,
				)
			} else {
				results.AddPassed(&function)
			}
		}
		return
	},
)

var CheckRestrictSourceArn = rules.Register(
	rules.Rule{
		AVDID:      "AVD-AWS-0067",
		Provider:   providers.AWSProvider,
		Service:    "lambda",
		ShortCode:  "restrict-source-arn",
		Summary:    "Ensure that lambda function permission has a source arn specified",
		Impact:     "Not providing the source ARN allows any resource from principal, even from other accounts",
		Resolution: "Always provide a source arn for Lambda permissions",
		Explanation: `When the principal is an AWS service, the ARN of the specific resource within that service to grant permission to. 

Without this, any resource from principal will be granted permission – even if that resource is from another account. 

For S3, this should be the ARN of the S3 Bucket. For CloudWatch Events, this should be the ARN of the CloudWatch Events Rule. For API Gateway, this should be the ARN of the API`,
		Links: []string{
			"https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-lambda-permission.html",
		},
		Terraform: &rules.EngineMetadata{
			GoodExamples:        terraformRestrictSourceArnGoodExamples,
			BadExamples:         terraformRestrictSourceArnBadExamples,
			Links:               terraformRestrictSourceArnLinks,
			RemediationMarkdown: terraformRestrictSourceArnRemediationMarkdown,
		},
		CloudFormation: &rules.EngineMetadata{
			GoodExamples:        cloudFormationRestrictSourceArnGoodExamples,
			BadExamples:         cloudFormationRestrictSourceArnBadExamples,
			Links:               cloudFormationRestrictSourceArnLinks,
			RemediationMarkdown: cloudFormationRestrictSourceArnRemediationMarkdown,
		},
		Severity: severity.Critical,
	},
	func(s *state.State) (results rules.Results) {
		for _, function := range s.AWS.Lambda.Functions {
			for _, permission := range function.Permissions {
				if !permission.Principal.EndsWith(".amazonaws.com") {
					continue
				}
				if permission.SourceARN.IsEmpty() {
					results.Add(
						"Lambda permission lacks source ARN for *.amazonaws.com principal.",
						permission.SourceARN,
					)
				} else {
					results.AddPassed(&function)
				}
			}
		}
		return
	},
)