Multiple Vulnerabilities in Microsoft Windows SMB Server Could Allow for Remote Code Execution (MS17-010)

ITS Advisory Number: 
2017-048
Date(s) Issued: 
Friday, May 12, 2017
Date Updated: 
Saturday, May 13, 2017
Subject: 
Multiple Vulnerabilities in Microsoft Windows SMB Server Could Allow for Remote Code Execution (MS17-010)
Overview: 

Multiple vulnerabilities have been discovered in Microsoft Windows SMB Server, the most severe of which could allow for remote code execution if an attacker sends specially crafted messages to a Microsoft Server Message Block 1.0 (SMBv1) server. Successful exploitation of the most severe of these vulnerabilities could result in an attacker gaining the same privileges as the logged on user. Depending on the privileges associated with the user, an attacker could then install programs; view, change, or delete data; or create new accounts with full user rights. Users whose accounts are configured to have fewer user rights on the system could be less impacted than those who operate with administrative user rights.

May 13, 2017 UPDATED OVERVIEW:

A recent spread of Ransomware has started exploiting this vulnerability. The Ransomewares known are named Wannacrypt0r, WannaCry, and WCry Ransomware. Once a system is infected, it will then encrypt the data of the system along with any accessible devices or media. It will continue to spread and infect any other systems on the network vulnerable to this attack.

Microsoft has included patches for older versions of their operating systems including Microsoft Windows XP, Windows 8 and Windows Server 2003.  

  • Microsoft Windows: XP, Vista, 7, 8.1, RT 8.1, 10
  • Microsoft Windows Server: 2003(All), 2008, 2008 R2, 2012, 2012 R2, 2016
Systems Affected: 
  • Microsoft Windows: XP, Vista, 7, 8.1, RT 8.1, 10
  • Microsoft Windows Server: 2003(All), 2008, 2008 R2, 2012, 2012 R2, 2016
RISK
GOVERNMENT
Large and medium government entities: 
High
Small government entities: 
High
BUSINESS
Large and medium business entities: 
High
Small business entities: 
High
Home Users: 
High
Description: 

Multiple vulnerabilities have been identified in Microsoft Windows SMB Server, the most severe of which could allow for remote code execution. The vulnerabilities are as follows:

  • Multiple remote code execution vulnerabilities exist due to the way the Microsoft Server Message Block 1.0 (SMBv1) server handles certain requests. (CVE-2017-0143, CVE-2017-0144, CVE-2017-0145, CVE-2017-0146, CVE-2017-148)
  • An information disclosure vulnerability exists due to the way the Microsoft Server Message Block 1.0 (SMBv1) server handles certain requests memory. (CVE-2017-0147)

To exploit these vulnerabilities an unauthenticated attacker could send a specially crafted packet to a targeted SMBv1 server. Successful exploitation of the most severe of these vulnerabilities could result in an attacker gaining the same privileges as the logged on user. Depending on the privileges associated with the user, an attacker could then install programs; view, change, or delete data; or create new accounts with full user rights. Users whose accounts are configured to have fewer user rights on the system could be less impacted than those who operate with administrative user rights.

** A recent spread of Ransomware has started exploiting this vulnerability. The Ransomewares known are named Wannacrypt0r, WannaCry, and WCry Ransomware. Once a system is infected, it will then encrypt the data of the system along with any accessible devices or media. It will continue to spread and infect any other systems on the network vulnerable to this attack. 

Actions: 
  • After appropriate testing, immediately apply patches provided by Microsoft to vulnerable systems.
  • Disable SMBv1 on all systems and utilize SMBv2 or SMBv3 after appropriate testing.
  • Run all software as a non-privileged user (one without administrative privileges) to diminish the effects of a successful attack.
  • Remind users not to visit un-trusted websites or follow links provided by unknown or un-trusted sources.
  • Inform and educate users regarding the threats posed by hypertext links contained in emails or attachments, especially those from un-trusted sources.
  • Apply the Principle of Least Privilege to all systems and services.