By Robert Brown

Spring is in the air and so are a number of bulletins! This month’s Patch Tuesday consists of 13 security bulletins – six critical and seven important – that remediate a total of 44 vulnerabilities.  Although the number of security bulletins is one of the highest seen this year, the overall number of fixes remains relatively low, which is good news for organizations ramping up their business activities this spring.

One of the critical bulletins (MS16-023) resolves 13 vulnerabilities in Internet Explorer. Five resolve issues in Internet Explorer 9, which was scheduled to be depreciated on the Windows 7 platform back in January. Organizations using this browser older than Internet Explorer 11 on Windows Vista SP2 or Windows Server 2008 SP2 can again breathe a sigh of relief as their browsers are updated for the second month in a row. Regardless of this update, it’s highly recommended to plan your migration to a new browser soon rather than later.

In addition to the browser updates, there are five other Remote Code Execution Vulnerabilities and four Elevations of Privilege, which should be a priority. All 13 patches recommend a reboot to ensure the vulnerability has been remediated. Unfortunately, this will be a headache for your users.   

Adobe to Release 6 Updates

February’s Microsoft updates contained a patch that specifically secures Flash within Microsoft Office. Adobe had its own updates for February in the release of APSB16-04 and will release six more updates with priority two classification this month.

As a point of interest, these updates are not yet being exploited. Affected products targeted by these critical vulnerabilities include Acrobat DC and Acrobat Reader DC 15.010.20059, Acrobat and Acrobat Reader DC 15.006.30119 and Acrobat XI and Reader XI 11.0.14 with earlier versions. Adobe is known for routinely sending patch updates to all its products with most vulnerabilities being discovered in-house. 

Near the end of 2015, Adobe released 70-plus patches between October and December. There were 77 released in December for Flash alone! They were all rated critical, and with the growing use of Flash by websites, this is a major concern for end users.

An article published in Security Week noted how Adobe released updates to patch a total of 460 vulnerabilities, which included more than 100 in Acrobat and Reader. The company fixed these with three security updates that were issued in May, July and October. Acrobat and Reader received security patches for 17 exploits, which also included memory corruption vulnerabilities. It seems obvious that these vulnerability numbers will only get higher.  Hopefully, Adobe will soon provide a solution to combat this issue.

Verismic recommends the following vulnerabilities be prioritized this month using vendor severity and CVSS scores; MS16-023 through MS16-030 paying particular attention to MS16-023, which is exposed to Internet Explorer memory corruption.

MS16-023 resolves vulnerabilities in Internet Explorer. If exposed, this vulnerability could allow remote-code execution if a user views a specially crafted web page using Internet Explorer. An attacker who successfully exploited this vulnerability could gain the same user rights as the current user. If this vulnerability is exploited on an administrator’s machine, the attacker will be able to create spoof admin accounts enabling him to take control of this system and others, removing AV protection and potentially stealing data.

The most severe of the vulnerabilities for MS16-024 could allow remote-code execution if a user views a specially crafted webpage using Microsoft Edge. It’s important to note that only Windows 10 is affected. This update resolves 11 vulnerabilities, the second highest in this baseline, and does require a reboot.

Exploiting MS16-025 could allow remote-code execution if Microsoft Windows fails to validate the input before loading certain libraries. However, this only impacts Windows Vista and Server 2008. This vulnerability is unlikely to reach mainstream companies.

MS16-026, MS16-027 and MS16-028 are similar in that they can only exploit a network if an attacker convinces a user to open a specially crafted document. A restart is recommended to complete this update.

An attacker who successfully exploited MS16-029 or MS16-030 could run arbitrary code in the context of the current user. However, those accounts that are configured to have fewer user rights on the system could be less impacted than those that operate with administrative user rights.

MS16-031 resolves a vulnerability in Microsoft Windows. The vulnerability could allow Elevation of Privilege if attackers are able to log on and enter a target system and run a specially crafted application. A reboot is required to complete this update.

MS16-032 is marked as important and uses a secondary logon to address Elevation of Privilege, which affects all supported versions of Windows. If the secondary logon service fails to manage memory requests correctly, then this will be exploited. A restart is recommended to complete this update.

MS16-033 resolves vulnerabilities in external access devices specifically specially crafted USBs. If inserted into a device, they could allow the attacker elevated privileges access to the system.  This patch is rated important, and a restart is recommended to complete this update.

MS16-034 blocks Elevation off Privilege if an attacker logs into the system and runs a specially crafted application to attack Windows Kernel-Mode drivers. It is rated important, and a restart is required to complete this update.

MS16-035 marks the third month in a row that Microsoft has released a similar .Net Framework update. This vulnerability bypasses the security features of .Net using a specially crafted XML document and is marked as important. A restart is recommended to complete this update.

The independent CVSS scores used in the table below range from 0 to 10. Vulnerabilities with a base score in the range 7.0-10.0 are High, those in the range 4.0-6.9 as Medium, and 0-3.9 as Low.

UPDATES

MS16-023–Cumulative Security Update for Internet Explorer (3142015)
(Impact: Remote Code Execution, Restart Requirement: Requires Restart, Severity: Critical, CVSS Score: 9.3)

This security update resolves vulnerabilities in Internet Explorer. The most severe of the vulnerabilities could allow remote-code execution if a user views a specially crafted webpage using Internet Explorer. An attacker who successfully exploited this vulnerability could gain the same user rights as the current user. If the current user is logged on with administrative user rights, an attacker who successfully exploited this vulnerability could take control of an affected system. An attacker could then install programs, as well as view, change and delete data or create new accounts with full user rights.

MS16-024–Cumulative Security Update for Microsoft Edge (3142019)
(Impact: Remote Code Execution, Restart Requirement: Requires Restart, Severity: Critical, CVSS Score: 9.3)

This security update resolves vulnerabilities in Microsoft Edge. The most severe of the vulnerabilities could allow remote-code execution if a user views a specially crafted webpage using Microsoft Edge. An attacker who successfully exploited the vulnerabilities could gain the same user rights as the current user. Customers whose accounts are configured to have fewer user rights on the system could be less impacted than those who operate with administrative user rights.

MS16-025–Security Update for Windows Library Loading to Address Remote Code Execution (3140709)
(Impact: Remote Code Execution, Restart Requirement: Requires Restart, Severity: Important, CVSS Score: 9.3)

This security update resolves a vulnerability in Microsoft Windows. The vulnerability could allow remote code execution if Microsoft Windows fails to properly validate input before loading certain libraries. However, an attacker must first gain access to the local system with the ability to execute a malicious application.

MS16-026–Security Update for Graphic Fonts to Address Remote Code Execution (3143148)
(Impact: Remote Code Execution, Restart Requirement: Requires Restart, Severity: Critical, CVSS Score: 9.3)

This security update resolves vulnerabilities in Microsoft Windows. The more severe of the vulnerabilities could allow remote-code execution if an attacker either convinces a user to open a specially crafted document or visit a webpage that contains specially crafted embedded OpenType fonts.

MS16-027–Security Update for Windows Media to Address Remote Code Execution (3143146)
(Impact: Remote Code Execution, Restart Requirement: May Require Restart, Severity: Critical, CVSS Score: 9.3)

This security update resolves vulnerabilities in Microsoft Windows. The vulnerabilities could allow remote-code execution if a user opens specially crafted media content that is hosted on a website.

MS16-028–Security Update for Microsoft Windows PDF Library to Address Remote Code Execution (3143081)
(Impact: Remote Code Execution, Restart Requirement: May Require Restart, Severity: Critical, CVSS Score: 9.3)

This security update resolves vulnerabilities in Microsoft Windows. The vulnerabilities could allow remote-code execution if a user opens a specially crafted PDF file.

MS16-029–Security Update for Microsoft Office to Address Remote Code Execution (3141806)
(Impact: Remote Code Execution, Restart Requirement: May Require Restart, Severity: Important, CVSS Score: 9.3)

This security update resolves vulnerabilities in Microsoft Office. The most severe of the vulnerabilities could allow remote code execution if a user opens a specially crafted Microsoft Office file. An attacker who successfully exploited the vulnerabilities could run arbitrary code in the context of the current user. Customers whose accounts are configured to have fewer user rights on the system could be less impacted than those who operate with administrative user rights.

MS16-030–Security Update for Windows OLE to Address Remote Code Execution (3143136)
(Impact: Remote Code Execution, Restart Requirement: Requires Restart, Severity: Important, CVSS Score: 9.3)

This security update resolves vulnerabilities in Microsoft Windows. The vulnerabilities could allow remote code execution if Windows OLE fails to properly validate user input. An attacker could exploit the vulnerabilities to execute malicious code. However, an attacker must first convince a user to open either a specially crafted file or a program from either a webpage or an email message.

MS16-031–Security Update for Microsoft Windows to Address Elevation of Privilege (3140410)
(Impact: Elevation of Privilege, Restart Requirement: Requires Restart, Severity: Important, CVSS Score: 7.2)

This security update resolves a vulnerability in Microsoft Windows. The vulnerability could allow elevation of privilege if an attacker is able to log on to a target system and run a specially crafted application.

MS16-032–Security Update for Secondary Logon to Address Elevation of Privilege (3143141)
(Impact: Elevation of Privilege, Restart Requirement: Requires Restart, Severity: Important, CVSS Score: 7.2)

This security update resolves a vulnerability in Microsoft Windows. The vulnerability could allow elevation of privilege if the Windows Secondary Logon Service fails to properly manage request handles in memory.

MS16-033–Security Update for Windows USB Mass Storage Class Driver to Address Elevation of Privilege (3143142)
(Impact: Elevation of Privilege, Restart Requirement: May Require Restart, Severity: Important, CVSS Score: 7.2)

This security update resolves a vulnerability in Microsoft Windows. The vulnerability could allow elevation of privilege if an attacker with physical access inserts a specially crafted USB device into the system.

MS16-034–Security Update for Windows Kernel-Mode Drivers to Address Elevation of Privilege (3143145)
(Impact: Elevation of Privilege, Restart Requirement: Requires Restart, Severity: Important, CVSS Score: 7.2)

This security update resolves vulnerabilities in Microsoft Windows. The vulnerabilities could allow elevation of privilege if an attacker logs on to the system and runs a specially crafted application.

MS16-035–Security Update for .NET Framework to Address Security Feature Bypass (3141780)
(Impact: Security Feature Bypass, Restart Requirement: May Require Restart, Severity: Important, CVSS Score: N/A)

This security update resolves a vulnerability in the Microsoft .NET Framework. The security feature bypass exists in a .NET Framework component that does not properly validate certain elements of a signed XML document.

Robert Brown is the director of services at Verismic, a global leader in cloud IT management technology, green solutions and business network software systems. Prior to his experience at Verismic, Brown developed competencies in SQL Server, Oracle and many Microsoft operating system platforms at FrontRange Solutions (UK) Limited.