SMB Security Best Practices

["US-CERT" <US-CERT () ncas us-cert gov>]

U.S. Department of Homeland Security US-CERT

National Cyber Awareness System:

 

SMB Security Best Practices [ https://www.us-cert.gov/ncas/current-activity/2017/01/16/SMB-Security-Best-Practices ] 
01/16/2017 11:45 PM EST 
Original release date: January 16, 2017 | Last revised: January 17, 2017

In response to public reporting of a potential Server Message Block (SMB) vulnerability, US-CERT is providing known 
best practices related to SMB. This service is universally available for Windows systems, and legacy versions of SMB 
protocols could allow a remote attacker to obtain sensitive information from affected systems.

US-CERT recommends that users and administrators consider:


  * disabling SMB v1 and 
  * blocking all versions of SMB at the network boundary by blocking TCP port 445 with related protocols on UDP ports 
137-138 and TCP port 139, for all boundary devices. 

US-CERT cautions users and administrators of potential issues that could be created by disabling SMB v1. For more 
information on SMB, review Microsoft Security Advisories 2696547 [ https://support.microsoft.com/en-us/kb/2696547 ] and 
204279 [ https://support.microsoft.com/en-us/kb/204279 ].

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