Ghost vulnerable to disclosure of private API fields

Vulnerability Description

Ghost is an app for new-media creators with tools to build a website, publish content, send newsletters, and offer paid subscriptions to members. Prior to version 5.46.1, due to a lack of validation when filtering on the public API endpoints, it is possible to reveal private fields via a brute force attack. Ghost(Pro) has already been patched. Maintainers can find no evidence that the issue was exploited on Ghost(Pro) prior to the patch being added. Self-hosters are impacted if running Ghost a version below v5.46.1. v5.46.1 contains a fix for this issue. As a workaround, add a block for requests to `/ghost/api/content/*` where the `filter` query parameter contains `password` or `email`.

References

• https://github.com/TryGhost/Ghost/security/advisories/GHSA-r97q-ghch-82j9
• https://github.com/TryGhost/Ghost/commit/b3caf16005289cc9909488391b4a26f3f4a66a90
• https://github.com/TryGhost/Ghost/releases/tag/v5.46.1