Windows SMB Information Disclosure Vulnerability

2017-05-11T07:00:00
ID MS:CVE-2017-0274
Type mscve
Reporter Microsoft
Modified 2017-05-11T07:00:00

Description

An information disclosure vulnerability exists in the way that the Microsoft Server Message Block 1.0 (SMBv1) server handles certain requests. An attacker who successfully exploited this vulnerability could craft a special packet, which could lead to information disclosure from the server.

To exploit the vulnerability, in most situations, an unauthenticated attacker could send a specially crafted packet to a targeted SMBv1 server.

The security update addresses the vulnerability by correcting how SMBv1 handles these specially crafted requests.

Disable SMBv1

For customers running Windows Vista and later See Microsoft Knowledge Base Article 2696547.

Alternative method for customers running Windows 8.1 or Windows Server 2012 R2 and later For client operating systems:

  1. Open Control Panel, click Programs, and then click Turn Windows features on or off.
  2. In the Windows Features window, clear the SMB1.0/CIFS File Sharing Support checkbox, and then click OK to close the window.
  3. Restart the system.

For server operating systems:

  1. Open Server Manager and then click the Manage menu and select Remove Roles and Features.
  2. In the Features window, clear the SMB1.0/CIFS File Sharing Support check box, and then click OK to close the window.
  3. Restart the system.

Impact of workaround. The SMBv1 protocol will be disabled on the target system.

How to undo the workaround. Retrace the workaround steps, and select the SMB1.0/CIFS File Sharing Support check box to restore the SMB1.0/CIFS File Sharing Support feature to an active state.