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.
Weakness
The product does not implement a required step in a cryptographic algorithm, resulting in weaker encryption than advertised by the algorithm.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Desktop | Nextcloud | 3.0.0 (including) | 3.8.0 (excluding) |
| Nextcloud | Nextcloud | 3.0.5 (including) | 4.8.0 (excluding) |
| Nextcloud | Nextcloud | 3.13.0 (including) | 3.25.0 (excluding) |
| Nextcloud-desktop | Ubuntu | focal | * |
| Nextcloud-desktop | Ubuntu | kinetic | * |
| Nextcloud-desktop | Ubuntu | lunar | * |
| Nextcloud-desktop | Ubuntu | mantic | * |
| Nextcloud-desktop | Ubuntu | oracular | * |
| Nextcloud-desktop | Ubuntu | plucky | * |
| Nextcloud-desktop | Ubuntu | trusty | * |
| Nextcloud-desktop | Ubuntu | xenial | * |
Related Attack Patterns
References
- https://ethz.ch/content/dam/ethz/special-interest/infk/inst-infsec/appliedcrypto/education/theses/report_DanieleCoppola.pdf
- https://github.com/nextcloud/desktop/pull/5560
- https://github.com/nextcloud/security-advisories/security/advisories/GHSA-8875-wxww-3rr8
- https://ethz.ch/content/dam/ethz/special-interest/infk/inst-infsec/appliedcrypto/education/theses/report_DanieleCoppola.pdf
- https://github.com/nextcloud/desktop/pull/5560
- https://github.com/nextcloud/security-advisories/security/advisories/GHSA-8875-wxww-3rr8