A remote code execution vulnerability exists when the Windows font library
improperly handles specially crafted embedded fonts. An attacker who
successfully exploited the vulnerability 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.
There are multiple ways an attacker could exploit the vulnerability:
- In a web-based attack scenario, an attacker could host a specially crafted website that is designed to exploit the vulnerability and then convince users to view the website. An attacker would have no way to force users to view the attacker-controlled content. Instead, an attacker would have to convince users to take action, typically by getting them to click a link in an email or instant message that takes users to the attacker's website, or by opening an attachment sent through email.
- In a file-sharing attack scenario, an attacker could provide a specially crafted document file that is designed to exploit the vulnerability and then convince users to open the document file. The security update addresses the vulnerability by correcting how the Windows font library handles embedded fonts.
Note that where the severity is indicated as Critical in the Affected Products
table, the Preview Pane is an attack vector for this vulnerability. The
security update addresses the vulnerability by correcting how the Windows font
library handles embedded fonts.