CVE-2021-32748 WOPI API not protected by credentials/IP check
Attackers can bypass document watermarks and download protections in Nextcloud Richdocuments due to missing WOPI API authentication checks.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2021-32748?
CVE-2021-32748 is a medium-severity missing authorization vulnerability in nextcloud security-advisories, published on 27 Jul 2021. Any signed-in user can exploit it over the network, with no action from the victim.
Official 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.
Weakness: CWE-862
Which versions are affected by CVE-2021-32748?
It affects 1 product.
Products include Nextcloud Richdocuments.
How do I fix CVE-2021-32748?
No fix has been published for CVE-2021-32748 yet. Limit exposure of the affected software until one is available.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2021-32748 being exploited?
There is no known exploitation of CVE-2021-32748 in the wild and no public exploit code.
Other vulnerabilities in nextcloud security-advisories
- CVE-2021-37628 File Drop can be bypassed using Richdocuments app in nextcloud
- CVE-2022-31024 Federated editing allows iframing remote servers by default in richdocuments
- CVE-2023-25150 Document content of files can be obtained through Collabora for files of other users
- CVE-2023-28645 Secure view can be bypassed by using internal API endpoint in Nextcloud richdocuments
- CVE-2021-37629 Lack of ratelimit on Richdocuments OCS endpoint in nextcloud
Sources
Also known as GHSA-24x8-h6m2-9jf2.