CVE-2020-0901
CriticalCVSS 9.8Exploitation Probability (EPSS)
Very high risk96th percentile - higher than 96% of all known CVEs
Summary
A remote code execution vulnerability exists in Microsoft Excel due to improper handling of objects in memory. An attacker can exploit it by convincing a user to open a specially crafted file, allowing arbitrary code execution in the context of the current user.
Risk Assessment
The risk to the organization includes system takeover if the user has administrative rights, and the ability to install programs, modify data, or create new accounts. The attack can be delivered via email or a malicious website.
Recommendation
Immediately install the security update from Microsoft that addresses the memory handling issue. Additionally, restrict user privileges and exercise caution when opening files from untrusted sources.
Original NVD description (English source)
A remote code execution vulnerability exists in Microsoft Excel software when the software fails to properly handle objects in memory. An attacker who successfully exploited the vulnerability could run arbitrary code in the context of the current user. If the current user is logged on with administrative user rights, an attacker could take control of the affected system. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights. Users whose accounts are configured to have fewer user rights on the system could be less impacted than users who operate with administrative user rights. Exploitation of the vulnerability requires that a user open a specially crafted file with an affected version of Microsoft Excel. In an email attack scenario, an attacker could exploit the vulnerability by sending the specially crafted file to the user and convincing the user to open the file. In a web-based attack scenario, an attacker could host a website (or leverage a compromised website that accepts or hosts user-provided content) containing a specially crafted file designed to exploit the vulnerability. An attacker would have no way to force users to visit the website. Instead, an attacker would have to convince users to click a link, typically by way of an enticement in an email or instant message, and then convince them to open the specially crafted file. The security update addresses the vulnerability by correcting how Microsoft Excel handles objects in memory.

