The AWS SDK for Ruby is an open-source client-side encryption library used to facilitate writing and reading encrypted records to S3. Missing cryptographic key commitment in the AWS SDK for Ruby may allow a user with write access to the S3 bucket to introduce a new EDK that decrypts to different plaintext when the encrypted data key is stored in an "instruction file" instead of S3's metadata record. To mitigate this issue, upgrade AWS SDK for Ruby to version 1.208.0 or later.