CVE-2016-9463 Information

Description

Nextcloud Server before 9.0.54 and 10.0.1 & ownCloud Server before 9.1.2 9.0.6 and 8.2.9 suffer from SMB User Authentication Bypass. Nextcloud/ownCloud include an optional and not by default enabled SMB authentication component that allows authenticating users against an SMB server. This backend is implemented in a way that tries to connect to a SMB server and if that succeeded consider the user logged-in. The backend did not properly take into account SMB servers that have any kind of anonymous auth configured. This is the default on SMB servers nowadays and allows an unauthenticated attacker to gain access to an account without valid credentials. Note: The SMB backend is disabled by default and requires manual configuration in the Nextcloud/ownCloud config file. If you have not configured the SMB backend then you’re not affected by this vulnerability.

CVSS Vector

CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

Reference

https://github.com/nextcloud/apps/commit/b85ace6840b8a6704641086bc3b8eb8e81cb2274 https://github.com/nextcloud/apps/commit/decb91fd31f4ffab191cbf09ce4e5c55c67a4087 https://github.com/owncloud/apps/commit/16cbccfc946c8711721fa684d78135ca1fb64791 https://github.com/owncloud/apps/commit/5d47e7b52646cf79edadd78ce10c754290cbb732 https://github.com/owncloud/apps/commit/a0e07b7ddd5a5fd850a6e07f8457d05b76a300b3 https://hackerone.com/reports/148151 https://nextcloud.com/security/advisory/?id=nc-sa-2016-006 https://owncloud.org/security/advisory/?id=oc-sa-2016-017 https://rhinosecuritylabs.com/2016/10/operation-ownedcloud-exploitation-post-exploitation-persistence/

Attack Complexity

HIGH

Privileges Required

NONE

User Interaction Required

NONE

Scope

NONE

Confidentiality Impact

UNCHANGED

Integrity Impact

HIGH

Availability Impact

HIGH

Base Score

HIGH

Base Severity

8.1