Nextcloud Server before 9.0.55 and 10.0.2 suffers from a permission increase on re-sharing via OCS API issue. A permission related issue within the OCS sharing API allowed an authenticated adversary to reshare shared files with an increasing permission set. This may allow an attacker to edit files in a share despite having only a 'read' permission set. Note that this only affects folders and files that the adversary has at least read-only permissions for.
Weaknesses in this category are related to improper assignment or handling of permissions.
The product specifies permissions for a security-critical resource in a way that allows that resource to be read or modified by unintended actors.
| Link | Tags |
|---|---|
| https://nextcloud.com/security/advisory/?id=nc-sa-2017-001 | patch vendor advisory |
| https://hackerone.com/reports/169680 | third party advisory |