Nextcloud · Nextcloud Server · CVE-2023-28833
**Name of the Vulnerable Software and Affected Versions**
Nextcloud Server versions prior to 24.0.10
Nextcloud Server versions prior to 25.0.4
**Description**
The issue is related to the lack of restrictions on file uploads in the Nextcloud server, allowing administrators to upload a logo or favicon with a maliciously named file, potentially overwriting files in the appdata directory. This could be exploited by tricking an administrator into uploading such a file. The vulnerability may allow a remote attacker to compromise the target system by uploading arbitrary files.
**Recommendations**
For Nextcloud Server versions prior to 24.0.10, upgrade to version 24.0.10.
For Nextcloud Server versions prior to 25.0.4, upgrade to version 25.0.4.
As a temporary workaround for users unable to upgrade, avoid ingesting logo files from untrusted sources.