Detects when an Amazon ECR repository or registry policy is modified to grant public access using a wildcard principal (Principal:"") statement. This rule analyzes SetRepositoryPolicy and PutRegistryPolicy events whose policy document grants an Allow effect to a wildcard ("") principal, indicating that pull (and potentially push) permissions were extended to all identities, including unauthenticated users. A public container registry can expose proprietary images and any secrets baked into their layers, and, if push is allowed, enables supply-chain implantation. Public ECR access is sometimes intentional for image distribution, so the granting principal and the permissions should be validated.

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