Nextcloud is an open-source productivity platform. In Nextcloud Desktop client 3.0.0 until 3.8.0, Nextcloud Android app 3.13.0 until 3.25.0, and Nextcloud iOS app 3.0.5 until 4.8.0, a malicious server administrator can gain full access to an end-to-end encrypted folder. They can decrypt files, recover the folder structure and add new files. This issue is fixed in Nextcloud Desktop 3.8.0, Nextcloud Android 3.25.0, and Nextcloud iOS 4.8.0. No known workarounds are available.
Exploitability
AV:PAC:LPR:HUI:RScope
S:CImpact
C:HI:HA:L6.9/CVSS:3.1/AV:P/AC:L/PR:H/UI:R/S:C/C:H/I:H/A:LOther