May 2020 Patch Tuesday

This month, Microsoft has patched 111 vulnerabilities with 13 of them being classified as Critical. This month had no disclosure of zero-days or other vulnerabilities prior to patching.

Visual Studio Code Python Extension

Where would we be without our favorite scripting language? Microsoft’s Python extension for Visual Studio Code, a free, lightweight, and cross-platform editor, was vulnerable to two remote code execution vulnerabilities. To exploit these vulnerabilities, an attacker would need to convince a target to clone a malicious repository and open it in Visual Studio Code, or open a maliciously crafted notebook file with Visual Studio Code. Both vulnerabilities require that the Python Extension is installed.

Microsoft’s Browsers

Microsoft’s Edge browser got some attention this month from vulnerabilities that could allow for remote code execution and elevation of privilege in a cross-domain context. Attackers would have to convince the victim to view malicious content via the usual attack vectors, such as phishing.

Internet Explorer had some memory corruption vulnerabilities patched and a remote code execution vulnerability involving the MSHTML engine that parses HTML code. Attackers exploiting these vulnerabilities would be able to glean sensitive information and execute code within the security context of the current user.

Microsoft Color Management

Microsoft’s color management library, ICM32.dll, was vulnerable to a remote code execution attack. Attackers would have to trick a user into visiting a malicious website, but would then be able to execute code within the security context of the web browser. This is particularly interesting because it is web browser-agnostic.

Microsoft SharePoint

Microsoft SharePoint is vulnerable to three remote code execution vulnerabilities. Each of these vulnerabilities involves failures to check the source markup of an application package. These vulnerabilities are particularly devastating as the code executed would be within the context of the SharePoint application pool and the SharePoint server farm account.