It's everyone's favorite Patch Tuesday, January's Patch Tuesday. Historically January has always been a light month for bulletins and this January is the lightest in years. With only four bulletins and three CVEs, Admins should have a relatively easy time this month.
Two bulletins are rated Critical. Both are arbitrary code execution vulnerabilities. One affects MS Office where a malicious document can trigger code execution when the victim opens it. The other is the omnipresent Adobe Flash where a malicious Flash element on a web page can also trigger code to run on the victim's system.
The other two bulletins are rated as Important. The first one is a privilege escalation vulnerability in the Edge browser. The second is a variant of an older Denial of Service vulnerability in LSASS. The original DoS vulnerability was patched back in November in bulletin MS16-137 (CVE-2016-7237). This new vulnerability affects LSASS in a very similar way, but in a different portion of the code. Also, unlike the vulnerability covered by MS16-137, this vulnerability only affects Windows 7 / Server 2008 R2 and lower.
That's it. All four vulnerabilities. So take a breath, kick your feet up, but don't relax for too long. While January has always been a light month, February is sure to come back with a vengeance.
Security Update for Microsoft Edge
This security update resolves a vulnerability in Microsoft Edge. This vulnerability could allow elevation of privilege if a user views a specially crafted webpage using Microsoft Edge. An attacker who successfully exploited the vulnerability could elevate privileges in affected versions of Microsoft Edge.
This security update is rated Important for Microsoft Edge on Windows 10 and Windows Server 2016.
Security Update for Microsoft Office
This security update resolves a vulnerability in Microsoft Office. The vulnerability could allow remote code execution if a user opens a specially crafted Microsoft Office file. An attacker who successfully exploited the vulnerability 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.
The security update addresses the vulnerability by correcting how affected versions of Office and Office components handle objects in memory.
See the full Microsoft bulletin for affected versions of Microsoft Office.
Security Update for Adobe Flash Player
This security update resolves vulnerabilities in Adobe Flash Player when installed on all supported editions of Windows 8.1, Windows Server 2012, Windows Server 2012 R2, Windows RT 8.1, Windows 10, and Windows Server 2016.
This security update is rated Critical. The update addresses the vulnerabilities in Adobe Flash Player by updating the affected Adobe Flash libraries contained within Internet Explorer 10, Internet Explorer 11, and Microsoft Edge.
Security Update for Local Security Authority Subsystem Service
A denial of service vulnerability exists in the way the Local Security Authority Subsystem Service (LSASS) handles authentication requests. An attacker who successfully exploited the vulnerability could cause a denial of service on the target system's LSASS service, which triggers an automatic reboot of the system.
This security update is rated Important for Microsoft Windows Vista, Windows Server 2008, Windows 7, and Windows Server 2008 R2 (and Server Core).