Incorrect permission assignment for critical resource in Nextcloud Server - CVE-2017-0883
Published: April 5, 2017 / Updated: August 8, 2020
Vulnerability identifier: #VU39271
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2017-0883
CWE-ID: CWE-732
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Nextcloud
Affected software:
Nextcloud Server
Nextcloud Server
Detailed vulnerability description
The vulnerability allows a remote authenticated user to read and manipulate data.
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.
How to mitigate CVE-2017-0883
Install update from vendor's website.