Description

Ghost: Stored XSS via Embed Card Previews

Impact

Embed cards in the Ghost editor could be used to bypass the fix for GHSA-8vhf-xxpj-4qrg. Any staff user, including Contributors, could store scripts in post content that ran when another staff user opened the post in the editor, possibly resulting in compromise of that user's admin session.

Self-hosted sites should leave the new security.embedPreviewUrl config option at its default.

Vulnerable versions

This vulnerability is present in Ghost from v6.34.0 up to v6.65.0.

Patches

v6.67.0 contains a fix for this issue.

How to update

For self-hosters using Docker, find Docker's official Ghost image here. Updating a Docker-based Ghost instance is documented here.

If your Ghost is a Ghost-CLI install see our documentation on updating it to the latest version here.

References

Ghost thanks DONG2209 (Dong Nguyen) and Pedro Pinho for disclosing this vulnerability responsibly.

For more information

If you have any questions or comments about this advisory, email us at security@ghost.org.

Mitigation

Aliases

References