Microsoft Security Response Center

**What kind of security feature could be bypassed by successfully exploiting this vulnerability?** An attacker who successfully exploited this vulnerability could bypass the Fast Identity Online (FIDO) secure authentication feature.

**What type of information could be disclosed by this vulnerability?** The type of information that could be disclosed if an attacker successfully exploited this vulnerability is memory layout - the vulnerability allows an attacker to collect information that facilitates predicting addressing of the memory.

**What privileges could be gained by an attacker who successfully exploited this vulnerability?** An attacker who successfully exploited this vulnerability could gain SYSTEM privileges.

**What type of information could be disclosed by this vulnerability?** This vulnerability makes it possible to listen to any group or user with a specially crafted group/username. By exploiting this vulnerability, the attacker can now receive messages for group(s) that they are unauthorized to view.

**How could an attacker exploit this vulnerability?** To exploit this vulnerability, an attacker would first have to log on to the system. An attacker could then run a specially crafted application that could exploit the vulnerability and take control of an affected system. Additionally, an attacker could convince a local user to open a malicious file. The attacker would have to convince the user 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.

**According to the CVSS metric, user interaction is required (UI:R). What interaction would the user have to do?** The user would have to click on install to be compromised by the attacker.

**Are the updates for the Microsoft Office for Mac currently available?** The security update for Microsoft Office 2019 for Mac and Microsoft Office LTSC for Mac 2021 are not immediately available. The updates will be released as soon as possible, and when they are available, customers will be notified via a revision to this CVE information.

**There are multiple update packages available for some of the affected software. Do I need to install all the updates listed in the Security Updates table for the software?** Yes. Customers should apply all updates offered for the software installed on their systems. If multiple updates apply, they can be installed in any order.

**Is the Preview Pane an attack vector for this vulnerability?** No, the Preview Pane is not an attack vector.

**What privileges could be gained by an attacker who successfully exploited this vulnerability?** An attacker who successfully exploited this vulnerability could gain SYSTEM privileges.