CVE-2021-39225 Missing permission check on Deck API
Authenticated users can access other users' Deck cards due to missing permission checks in the Nextcloud Deck application.
- 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-2021-39225?
CVE-2021-39225 is a high-severity missing authorization vulnerability in nextcloud security-advisories, published on 25 Oct 2021. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Nextcloud is an open-source, self-hosted productivity platform. A missing permission check in Nextcloud Deck before 1.2.9, 1.4.5 and 1.5.3 allows another authenticated users to access Deck cards of another user. It is recommended that the Nextcloud Deck App is upgraded to 1.2.9, 1.4.5 or 1.5.3. There are no known workarounds aside from upgrading.
Which versions are affected by CVE-2021-39225?
It affects 1 product.
Products include Nextcloud Deck.
How do I fix CVE-2021-39225?
No fix has been published for CVE-2021-39225 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-2021-39225 being exploited?
There is no known exploitation of CVE-2021-39225 in the wild and no public exploit code.
Other vulnerabilities in nextcloud security-advisories
- CVE-2020-8182 Missing authorization in Nextcloud Deck
- CVE-2021-37631 Circle can be accessed by non-Circle members in Nextcloud Deck
- CVE-2021-22913 Information disclosure in Nextcloud Deck
- CVE-2023-22469 Nextcloud Deck card vulnerable to data leak to unauthorized users via reference preview cache
- CVE-2025-66557 Nextcloud Deck app allowed user with "Can share" permission to modify permissions of other non-owners
Sources
Also known as GHSA-2x96-38qg-3m72.