Microsoft released its monthly set of security updates today for a variety of its products that address a variety of bugs. The latest Patch Tuesday covers 61 vulnerabilities, 17 of which are rated "critical," 43 that are rated "important" and one that is considered to have "moderate" severity.

The advisories cover bugs in the Internet Explorer web browser, Jet Database Engine and the Chakra scripting engine, among other products and software.

This update also includes two critical advisories, one of which covers security updates to Adobe Flash, and another that deals with a denial-of-service vulnerability in the Microsoft Windows operating system.

Critical vulnerabilities
Microsoft released coverage for 17 critical bugs. Cisco Talos believes 16 of these are of special importance and need to be addressed by users immediately.

CVE-2018-0965 is a remote code execution vulnerability in the Windows Hyper-V hypervisor. An attacker can exploit this vulnerability by running a specially crafted application on a guest system that would cause the system operating Hyper-V to execute arbitrary code. The flaw lies in the way that Hyper-V validates inputs from an authenticated user on a guest OS.

CVE-2018-8367 is a remote code execution vulnerability in the Chakra scripting engine. The engine improperly handles objects in memory in the Microsoft Edge web browser that could allow an attacker to corrupt the system's memory and execute arbitrary code with the user's credentials.

CVE-2018-8420 is a remote code execution vulnerability in Microsoft XML Core Services MSXML. An attacker could trick the user into visiting a specially crafted, malicious website designed to invoke MSXML through a web browser, allowing the attacker to eventually run code and take control of the user's system.

CVE-2018-8461 is a remote code execution vulnerability in Internet Explorer that exists when the web browser improperly accesses objects in memory. This bug could corrupt memory in a way that an attacker could execute arbitrary code with the same rights as the current user. A user would need to visit a specially crafted, malicious website to trigger this vulnerability.

CVE-2018-8475 is a remote code execution vulnerability in Windows OS, which exists due to the image-loading functionality improperly handling malformed image files. An attacker could exploit this bug by convincing a user to load a malformed image file from either a web page, email or other method.

CVE-2018-8332 is a remote code execution vulnerability in the Windows font library. There are multiple ways in which an attacker could exploit this flaw, including convincing the user to click on a malicious web page or providing the user with a specially crafted, malicious document.

CVE-2018-8391 is a remote code execution vulnerability in the Chakra scripting engine. An attacker can exploit this flaw if a user is logged on with an administrative account.

CVE-2018-8439 is a remote code execution vulnerability in the Windows Hyper-V hypervisor. The bug exists in Hyper-V's validation on a host server. An attacker can exploit this flaw by running a specially crafted application on a guest operating system that could lead to the machine running Hyper-V executing arbitrary code.

CVE-2018-8447 is a remote code execution vulnerability in Internet Explorer. An attacker could exploit this vulnerability by tricking a user into visiting a specially crafted web page while using the Internet Explorer browser, or by taking advantage of a compromised website through advertisements or attachments that the user would have to click on.

CVE-2018-8456 and CVE-2018-8459 are remote code execution vulnerabilities that exist in the Chakra scripting engine's handling of objects in memory. This bug could corrupt memory in a way that an attacker could execute arbitrary code with the same rights as the current user.

CVE-2018-8457 is a remote code execution vulnerability that exists in the way Microsoft web browsers' scripting engines handle objects in memory. An attacker could host a specially crafted website to exploit this vulnerability, and then convince the user to visit the website while using a Microsoft web browser, or they could embed an ActiveX control that is marked "safe for initialization" in a Microsoft Office file or an application that hosts the browser's rendering engine.

CVE-2018-8464 is a remote code execution vulnerability in Microsoft Edge's PDF reader that exists in the way the reader handles objects in memory. An attacker could exploit this bug by convincing a user to click on a web page that contains a malicious PDF, or by hosting the PDF on websites that host user-provided content.

CVE-2018-8465, CVE-2018-8466 and CVE-2018-8467 are remote code execution vulnerabilities in the Chakra scripting engine that lie in the way it handles objects in memory in the Microsoft Edge web browser. An attacker can exploit these bugs by tricking the user into opening a malicious web page, or an advertisement that is hosted on a website that allows user-provided content.

The other critical vulnerability is:

Important vulnerabilities
There is also coverage for 43 important vulnerabilities, 11 of which we wish to highlight.

CVE-2018-8354 is a remote code execution vulnerability that exists in the way the scripting engine handles objects in memory in the Microsoft Edge web browser. A user would need to visit a specially crafted, malicious website in order to trigger this vulnerability.

CVE-2018-8392 and CVE-2018-8393 are buffer overflow vulnerabilities in the Microsoft Jet Database Engine. To exploit these bugs, a user must open a specially crafted Excel file while using an at-risk version of Windows. An attacker could exploit these vulnerabilities to execute code on the victim's machine at an administrator's level.

CVE-2018-8430 is a remote code execution vulnerability in Microsoft Word 2013 and 2016. An attacker can exploit this by tricking a user into opening a specially crafted, malicious PDF.

CVE-2018-8447 is an elevation of privilege vulnerability that lies in the way Windows processes calls to Advanced Local Procedure Call (ALPC). An attacker would need to log onto the system directly in order to exploit this vulnerability, and then run a specially crafted application.

CVE-2018-8331 is a remote code execution vulnerability in Microsoft Excel that exists when the software fails to correctly handle objects in memory. A user could trigger this bug by opening a specially crafted, malicious file in an email or on a web page.

CVE-2018-8315is an information disclosure vulnerability in Microsoft's scripting engine that could expose uninitialized memory if exploited. An attacker could access this information by convincing a user to visit a malicious website and then leveraging the vulnerability to obtain privileged data from the browser process.

CVE-2018-8335 is a denial-of-service vulnerability in the Microsoft Server Block Message (SMB). An attacker can send a specially crafted request to the server to trigger this vulnerability.

CVE-2018-8425 is a spoofing vulnerability in the Microsoft Edge web browser. The bug lies in the way the browser handles specific HTML content. If an attacker correctly exploits this bug, a user could be tricked into thinking they are visiting a legitimate website when they are actually on a malicious page.

CVE-2018-8440 is an elevation of privilege vulnerability that occurs when Windows incorrectly handles calls to Advanced Local Procedure Call (APLC). An attacker needs to log onto the system directly to exploit this vulnerability, and then run a specially crafted application to take over the system. This vulnerability has been spotted in the wild as part of several pieces of malware.

The other vulnerabilities that are rated "important" are:

Coverage
In response to these vulnerability disclosures, Talos is releasing the following Snort rules that detect attempts to exploit them. Please note that additional rules may be released at a future date and current rules are subject to change pending additional information. Firepower customers should use the latest update to their ruleset by updating their SRU. Open Source Snort Subscriber Rule Set customers can stay up-to-date by downloading the latest rule pack available for purchase on Snort.org.

Snort Rules: 45142-45143, 47702-47703, 47717-47718, 47730-47741, 47745-47748