SB2017032809 - Multiple vulnerabilities in Nextcloud Server



SB2017032809 - Multiple vulnerabilities in Nextcloud Server

Published: March 28, 2017 Updated: July 18, 2020

Security Bulletin ID SB2017032809
Severity
High
Patch available
YES
Number of vulnerabilities 4
Exploitation vector Remote access
Highest impact Code execution

Breakdown by Severity

High 25% Medium 25% Low 50%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 4 secuirty vulnerabilities.


1) Cross-site scripting (CVE-ID: CVE-2016-9465)

The disclosed vulnerability allows a remote attacker to perform cross-site scripting (XSS) attacks.

The vulnerability exists due to insufficient sanitization of user-supplied data. A remote attacker can permanently inject and execute arbitrary HTML and script code in user's browser in context of vulnerable website.

Successful exploitation of this vulnerability may allow a remote attacker to steal potentially sensitive information, change appearance of the web page, perform phishing and drive-by-download attacks.


2) Cross-site scripting (CVE-ID: CVE-2016-9466)

The vulnerability allows a remote non-authenticated attacker to read and manipulate data.

Nextcloud Server before 10.0.1 & ownCloud Server before 9.0.6 and 9.1.2 suffer from Reflected XSS in the Gallery application. The gallery app was not properly sanitizing exception messages from the Nextcloud/ownCloud server. Due to an endpoint where an attacker could influence the error message, this led to a reflected Cross-Site-Scripting vulnerability.


3) Improper access control (CVE-ID: CVE-2016-9467)

The vulnerability allows a remote non-authenticated attacker to manipulate data.

Nextcloud Server before 9.0.54 and 10.0.1 & ownCloud Server before 9.0.6 and 9.1.2 suffer from content spoofing in the files app. The location bar in the files app was not verifying the passed parameters. An attacker could craft an invalid link to a fake directory structure and use this to display an attacker-controlled error message to the user.


4) Improper Authentication (CVE-ID: CVE-2016-9463)

The vulnerability allows a remote non-authenticated attacker to execute arbitrary code.

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.


Remediation

Install update from vendor's website.

References