No Function Policy Wildcards

Function policies should avoid use of wildcards and instead apply the principle of least privilege

You should use the principle of least privilege when defining your IAM policies. This means you should specify each exact permission required without using wildcards, as this could cause the granting of access to certain undesired actions, resources and principals.

Impact

Overly permissive policies may grant access to sensitive resources

Recommended Actions

Follow the appropriate remediation steps below to resolve the issue.

Specify the exact permissions required, and to which resources they should apply instead of using wildcards.

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AWSTemplateFormatVersion: 2010-09-09
Description: Good Example of SAM Function
Resources:
  GoodFunction:
    Type: AWS::Serverless::Function
    Properties:
      PackageType: Image
      ImageUri: account-id.dkr.ecr.region.amazonaws.com/ecr-repo-name:image-name
      ImageConfig:
        Command:
          - "app.lambda_handler"
        EntryPoint:
          - "entrypoint1"
        WorkingDirectory: "workDir"
      Policies:  
        - AWSLambdaExecute
        - Version: '2012-10-17'
          Statement:
          - Effect: Allow
            Action:
            - s3:GetObject
            - s3:GetObjectACL
            Resource: 'arn:aws:s3:::my-bucket/*'

Function policies should avoid use of wildcards and instead apply the principle of least privilege

Impact

Recommended Actions

Links