CVE-2016-9463 Auth bypass in Nextcloud Server & ownCloud Server Nextcloud Server before 9.0.54 and 10.0.1 & ownCloud Server before 9.1.2, 9.0.6, and 8.2.9

High 8.1 Published Updated

An unauthenticated attacker can bypass authentication and access accounts if the optional SMB backend is configured with anonymous access enabled.

Exploited in the wild
Not known
Login needed
Not needed
Attackable
Over the internet
Victim action needed
Not needed
Fix
None listed

What is CVE-2016-9463?

CVE-2016-9463 is a high-severity authentication bypass vulnerability in Nextcloud Nextcloud Server, published on 28 Mar 2017. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official 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.

Weakness: CWE-287, CWE-303

Which versions are affected by CVE-2016-9463?

It affects 2 products.

Products include Nextcloud Nextcloud Server, Owncloud Owncloud.

How do I fix CVE-2016-9463?

No fix has been published for CVE-2016-9463 yet. Limit exposure of the affected software until one is available.

Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.

Is CVE-2016-9463 being exploited?

There is no known exploitation of CVE-2016-9463 in the wild and no public exploit code.

All Nextcloud Nextcloud Server vulnerabilities

Sources

Also known as GHSA-4r4x-7f2r-2f4c.

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