CVE-2023-48239 Nextcloud Server users can make external storage mount points inaccessible for other users
A malicious user can modify external storage configurations to make them inaccessible to other users, causing denial of service.
- 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-2023-48239?
CVE-2023-48239 is a high-severity missing authorization vulnerability in Nextcloud Nextcloud Server, published on 21 Nov 2023. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Nextcloud Server provides data storage for Nextcloud, an open source cloud platform. Starting in version 25.0.0 and prior to versions 25.0.13, 26.0.8, and 27.1.3 of Nextcloud Server and starting in version 20.0.0 and prior to versions 20.0.14.16, 21.0.9.13, 22.2.10.15, 23.0.12.12, 24.0.12.8, 25.0.13, 26.0.8, and 27.1.3 of Nextcloud Enterprise Server, a malicious user could update any personal or global external storage, making them inaccessible for everyone else as well. Nextcloud Server 25.0.13, 26.0.8, and 27.1.3 and Nextcloud Enterprise Server is upgraded to 20.0.14.16, 21.0.9.13, 22.2.10.15, 23.0.12.12, 24.0.12.8, 25.0.13, 26.0.8, and 27.1.3 contain a patch for this issue. As a workaround, disable app files_external. This workaround also makes the external storage inaccessible but retains the configurations until a patched version has been deployed.
Weakness: CWE-284
Which versions are affected by CVE-2023-48239?
It affects 1 product.
Products include Nextcloud Nextcloud Server.
How do I fix CVE-2023-48239?
No fix has been published for CVE-2023-48239 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-2023-48239 being exploited?
There is no known exploitation of CVE-2023-48239 in the wild and no public exploit code.
Other vulnerabilities in Nextcloud Nextcloud Server
- CVE-2021-32802 Preview generation used third-party library not suited for user-generated content in Nextcloud server
- CVE-2023-26482 Scope of workflow operations is not validated in nextcloud server
- CVE-2018-3775 Auth bypass in Nextcloud Server
- CVE-2023-35172 Nextcloud Server password reset endpoint is not brute force protected
- CVE-2023-32320 Nextcloud Server's brute force protection allows someone to send more requests than intended
Sources
Also known as GHSA-f962-hw26-g267.