Vault GitHub Action did not correctly mask multi-line secrets in output

HashiCorp vault-action (aka Vault GitHub Action) before 2.2.0 allows attackers to obtain sensitive information from log files because a multi-line secret was not correctly registered with GitHub Actions for log masking.

The vault-action implementation did not correctly handle the marking of multi-line variables. As a result, multi-line secrets were not correctly masked in vault-action output.

Remediation:
Customers using vault-action should evaluate the risk associated with this issue, and consider upgrading to vault-action 2.2.0 or newer. Please refer to https://github.com/marketplace/actions/hashicorp-vault for more information.