Welcome back to this month’s Patch Tuesday. Microsoft has patched 49 vulnerabilities this month, including several that had details disclosed prior to patching, and one “zero-day” vulnerability in Windows that was actively being exploited was also patched. 12 of the vulnerabilities were rated as Critical. The bulk of the vulnerabilities focus on web browsers and Office. Notably, Adobe Flash Player did not receive a fix this month.
Internet Explorer and Edge
As usual, Internet Explorer and Edge received a considerable number of fixes. Two notable fixes were for CVE-2018-8473 and CVE-2018-8460 for Edge and Internet Explorer respectively. Both vulnerabilities have remote code execution impacts, within the security context of the current user. Once again this serves as a frequent reminder to exercise the principle of least privilege.
The Windows Kernel received two fixes this month, with impacts of Information Disclosure and Elevation of Privilege. An attacker exploiting these vulnerabilities would have system-level privileges, allowing them to take full control of the affected system. Typically, these attacks would have to be carried out by a local attacker, or someone with credentialed access. However, an attacker exploiting a remote code execution vulnerability may be able to leverage these vulnerabilities in conjunction to further compromise the system.
Office received fixes for nine vulnerabilities this month. A few of them, CVE-2018-8504, CVE-2018-8502, and CVE-2018-8501, allowed for remote code execution that would give the attacker full control over the system. The vulnerabilities reside in the handling of objects in memory, where an application parsing the maliciously crafted content would enter a vulnerable state and allow attackers to execute their code.
One notable vulnerability fixed this month for Windows itself was CVE-2018-8453, which was being actively exploited by the cyber-espionage group known as FruityArmor. The group has previously used other zero-day exploits for Windows Graphics, and Adobe Flash Player. The group has deployed exploits of this vulnerability primarily in the Middle East. This vulnerability allowed for elevation of privilege from the win32k component, which allowed an attacker that had already gained a foothold on a system to gain full control of the system.