The Surfer WordPress plugin before 1.8.1.759 discloses a sensitive API credential to low-privileged users through the post editor page and relies on that same credential as the sole authorization for its privileged REST API, allowing users with contributor-level access and above to read the credential and escalate to publishing arbitrary posts and other privileged actions.
https://wpscan.com/vulnerability/0cc6b6cd-ff1a-4f04-a2f5-62684abeb314/