CVE-2016-9463: High severity nextcloud server vulnerability
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.
Affected Software
Remediation
Patch Available
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Frequently Asked Questions
What is the severity of CVE-2016-9463?
CVE-2016-9463 is classified as a medium severity vulnerability affecting Nextcloud and ownCloud servers.
How do I fix CVE-2016-9463?
To fix CVE-2016-9463, update Nextcloud Server to version 9.0.54 or later and 10.0.1 or later, and ownCloud Server to version 9.1.2, 9.0.6, or 8.2.9 or later.
Which software versions are affected by CVE-2016-9463?
CVE-2016-9463 affects Nextcloud Server versions prior to 9.0.54 and 10.0.0, as well as ownCloud Server versions prior to 9.1.2, 9.0.6, and 8.2.9.
What type of vulnerability is CVE-2016-9463?
CVE-2016-9463 is an SMB user authentication bypass vulnerability in Nextcloud and ownCloud servers.
Is SMB authentication enabled by default in Nextcloud or ownCloud?
No, the SMB authentication component in Nextcloud and ownCloud is optional and not enabled by default.