Impact
Nextcloud uses the WOPI ("Web Application Open Platform Interface") protocol to communicate with the Collabora Editor, the communication between these two services was not protected by a credentials or IP check.
Whilst this does not result in gaining access to data that the user has not yet access to, it can result in a bypass of any enforced watermark on documents as described on the Nextcloud Virtual Data Room website and our documentation.
Patches
The Nextcloud Richdocuments releases 3.8.3 and 4.2.0 add an additional admin settings for an allowlist of IP addresses that can access the WOPI API. We recommend upgrading and configuring the allowlist to a list of Collabora servers.
Workarounds
There is no known workaround. Note that this primarily results a bypass of any configured watermark or download protection using File Access Control. If you do not require or rely on these as a security feature no immediate action is required on your end.
References
For more information
If you have any questions or comments about this advisory:
Impact
Nextcloud uses the WOPI ("Web Application Open Platform Interface") protocol to communicate with the Collabora Editor, the communication between these two services was not protected by a credentials or IP check.
Whilst this does not result in gaining access to data that the user has not yet access to, it can result in a bypass of any enforced watermark on documents as described on the Nextcloud Virtual Data Room website and our documentation.
Patches
The Nextcloud Richdocuments releases 3.8.3 and 4.2.0 add an additional admin settings for an allowlist of IP addresses that can access the WOPI API. We recommend upgrading and configuring the allowlist to a list of Collabora servers.
Workarounds
There is no known workaround. Note that this primarily results a bypass of any configured watermark or download protection using File Access Control. If you do not require or rely on these as a security feature no immediate action is required on your end.
References
For more information
If you have any questions or comments about this advisory: