Security Advisory

Improper access control checks for share expiration date (NC-SA-2019-002)

12th April 2019

Risk level: Low

CVSS v3 Base Score: 4.8 (AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N)

CWE: Improper Access Control - Generic (CWE-284)

HackerOne report: 447494

Description

A missing check could give recipient the possibility to extend the expiration date of a share they received.

Affected Software

• Nextcloud Server < 15.0.0 (CVE-2020-8122)
• Nextcloud Server < 14.0.4 (CVE-2020-8122)
• Nextcloud Server < 13.0.8 (CVE-2020-8122)
• Nextcloud Server < 12.0.13 (CVE-2020-8122)

Action Taken

The error has been fixed.

Resolution

It is recommended that all instances are upgraded to Nextcloud 15.0.0, Nextcloud 14.0.4, Nextcloud 13.0.8 or 12.0.13.

Acknowledgements

The Nextcloud team thanks the following people for their research and responsible disclosure of the above advisory:

• Carl Pearson - Vulnerability discovery and disclosure.

This advisory is licensed CC BY-SA 4.0.