GHSA-322m-ff4g-9vx9: SSRF
Impact
A validation issue allowed some functionality, such as Webmentions, to be abused by an unauthenticated user to make limited HTTP requests to hosts in the Ghost server's internal network. A successful attack would not result in any response data being returned.
Vulnerable versions
This vulnerability is present in Ghost from v6.54.1 up to v6.64.0.
Patches
v6.65.0 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 Nhat Anh Vu for disclosing this vulnerability responsibly.
For more information
If you have any questions or comments about this advisory, email us at security@ghost.org.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
npm/ghostto a version that resolves this vulnerability.Fixed in 6.65.0 - Upgrade
Upgrade
Ghostto a version that resolves this vulnerability.Fixed in 6.65.0
Event History
Frequently Asked Questions
Which deployments are affected?
Ghost versions from 6.54.1 through 6.64.0 are affected. Version 6.65.0 contains the fix.
What does an attacker need to exploit this issue?
An attacker does not need authentication or user interaction. Exploitation has high attack complexity and can abuse functionality such as Webmentions to make limited HTTP requests to hosts on the Ghost server's internal network.
Can an attacker read data from internal services?
No response data is returned from the requests made through this issue. The described impact is limited HTTP requests to internal-network hosts.
What should self-hosted operators do?
Update Ghost to version 6.65.0 or later. Docker-based installations can be updated using the official Ghost image and documented Docker update process; Ghost-CLI installations should follow the documented Ghost update process.