Vulnerability Monitor

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CVE-2016-9463

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.

Security Impact Summary

This vulnerability carries a HIGH severity rating with a CVSS v3.1 score of 8.1, indicating it can be exploited remotely over the network but requires specific conditions to be met without requiring user interaction and does not require pre-existing privileges . The vulnerability impacts confidentiality (data exposure), integrity (unauthorized modifications), and availability (service disruption) for affected systems. Impacting 2 products from nextcloud, from owncloud organizations running these solutions should prioritize assessment and patching.

Historical Context

First disclosed in 2017, this vulnerability was reported during a period defined by widespread IoT adoption challenges, mobile security concerns, and the emergence of advanced persistent threat (APT) techniques. Contemporary mitigation strategies focused on secure development practices and third-party component vetting.

Published

2017-03-28T02:59:00.933

Last Modified

2025-04-20T01:37:25.860

Status

Deferred

Source

[email protected]

Severity

CVSSv3.0: 8.1 (HIGH)

CVSSv2 Vector

AV:N/AC:M/Au:N/C:P/I:P/A:P

Access Vector: NETWORK
Access Complexity: MEDIUM
Authentication: NONE
Confidentiality Impact: PARTIAL
Integrity Impact: PARTIAL
Availability Impact: PARTIAL

Exploitability Score

8.6

Impact Score

6.4

Weaknesses

Type: Secondary
CWE-303
Type: Primary
CWE-287

Affected Vendors & Products

Type	Vendor	Product	Version/Range	Vulnerable?
Application	nextcloud	nextcloud_server	< 9.0.54	Yes
Application	nextcloud	nextcloud_server	< 10.0.1	Yes
Application	owncloud	owncloud	< 8.2.9	Yes
Application	owncloud	owncloud	< 9.0.4	Yes
Application	owncloud	owncloud	< 9.1.2	Yes

References

https://github.com/nextcloud/apps/commit/b85ace6840b8a6704641086bc3b8eb8e81cb2274 Issue Tracking, Patch, Third Party Advisory ([email protected])
https://github.com/nextcloud/apps/commit/decb91fd31f4ffab191cbf09ce4e5c55c67a4087 Issue Tracking, Patch, Third Party Advisory ([email protected])
https://github.com/owncloud/apps/commit/16cbccfc946c8711721fa684d78135ca1fb64791 Issue Tracking, Patch, Third Party Advisory ([email protected])
https://github.com/owncloud/apps/commit/5d47e7b52646cf79edadd78ce10c754290cbb732 Issue Tracking, Patch, Third Party Advisory ([email protected])
https://github.com/owncloud/apps/commit/a0e07b7ddd5a5fd850a6e07f8457d05b76a300b3 Issue Tracking, Patch, Third Party Advisory ([email protected])
https://hackerone.com/reports/148151 Exploit, Third Party Advisory ([email protected])
https://nextcloud.com/security/advisory/?id=nc-sa-2016-006 Patch, Vendor Advisory ([email protected])
https://owncloud.org/security/advisory/?id=oc-sa-2016-017 Patch, Vendor Advisory ([email protected])
https://rhinosecuritylabs.com/2016/10/operation-ownedcloud-exploitation-post-exploitation-persistence/ Exploit, Technical Description, Third Party Advisory ([email protected])
https://github.com/nextcloud/apps/commit/b85ace6840b8a6704641086bc3b8eb8e81cb2274 Issue Tracking, Patch, Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://github.com/nextcloud/apps/commit/decb91fd31f4ffab191cbf09ce4e5c55c67a4087 Issue Tracking, Patch, Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://github.com/owncloud/apps/commit/16cbccfc946c8711721fa684d78135ca1fb64791 Issue Tracking, Patch, Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://github.com/owncloud/apps/commit/5d47e7b52646cf79edadd78ce10c754290cbb732 Issue Tracking, Patch, Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://github.com/owncloud/apps/commit/a0e07b7ddd5a5fd850a6e07f8457d05b76a300b3 Issue Tracking, Patch, Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://hackerone.com/reports/148151 Exploit, Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://nextcloud.com/security/advisory/?id=nc-sa-2016-006 Patch, Vendor Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://owncloud.org/security/advisory/?id=oc-sa-2016-017 Patch, Vendor Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://rhinosecuritylabs.com/2016/10/operation-ownedcloud-exploitation-post-exploitation-persistence/ Exploit, Technical Description, Third Party Advisory (af854a3a-2127-422b-91ae-364da2661108)

How SecUtils Interprets This CVE

SecUtils normalizes and enriches National Vulnerability Database (NVD) records by standardizing vendor and product identifiers, aggregating vulnerability metadata from both NVD and MITRE sources, and providing structured context for security teams. For nextcloud's affected products, we extract Common Platform Enumeration (CPE) data, Common Weakness Enumeration (CWE) classifications, CVSS severity metrics, and reference data to enable rapid vulnerability prioritization and asset correlation. This record contains no exploit code, proof-of-concept instructions, or attack methodologies—only defensive intelligence necessary for patch management, risk assessment, and security operations.