CVE-2021-32748: Nextcloud Richdocuments in an open source self hosted online office. Nextcloud uses the WOPI ("Web Application Open Platform Interface") protocol to c...

Description

Nextcloud Richdocuments in an open source self hosted online office. 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](https://nextcloud.com/virtual-data-room/) website and [our documentation](https://portal.nextcloud.com/article/nextcloud-and-virtual-data-room-configuration-59.html). 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. 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.

Metrics

CVSS 3.1

4.3/10

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

EPSS Probability

0.99%

57.9th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Nextcloud	Richdocuments	< 3.8.3
Nextcloud	Richdocuments	>= 4.0.0, < 4.2.0

References

https://github.com/nextcloud/richdocuments/pull/1640Third Party Advisory
https://github.com/nextcloud/security-advisories/security/advisories/GHSA-24x8-h6m2-9jf2Third Party Advisory
https://hackerone.com/reports/1194606Permissions Required
https://github.com/nextcloud/richdocuments/pull/1640Third Party Advisory
https://github.com/nextcloud/security-advisories/security/advisories/GHSA-24x8-h6m2-9jf2Third Party Advisory
https://hackerone.com/reports/1194606Permissions Required

Timeline

Published: Jul 27, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-32748?

Nextcloud Richdocuments in an open source self hosted online office. 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](https://nextcloud.com/virtual-data-room/) website and [our documentation](https://portal.nextcloud.com/article/nextcloud-and-virtual-data-room-configuration-59.html). 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. 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.

How severe is CVE-2021-32748?

CVE-2021-32748 has a CVSS score of 4.3/10 (MEDIUM severity). The EPSS model estimates a 0.99% probability of exploitation in the next 30 days.

How do I fix CVE-2021-32748?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.