Critical CVSS 7.8 EPSS 0.22501 2020-07 archive

Executive Summary

A remote code execution vulnerability exists in Microsoft Outlook software when it fails to properly handle objects in memory. An attacker who successfully exploited the vulnerability could use a specially crafted file to perform actions in the security context of the current user. For example, the file could then take actions on behalf of the logged-on user with the same permissions as the current user. To exploit the vulnerability, a user must open a specially crafted file with an affected version of Microsoft Outlook software. 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) that contains a specially crafted file that is designed to exploit the vulnerability. However, an attacker would have no way to force the user to visit the website. Instead, an attacker would have to convince the user to click a link, typically by way of an enticement in an email or Instant Messenger message, and then convince the user to open the specially crafted file. Note that the Preview Pane is an attack vector for this vulnerability. The security update addresses the vulnerability by correcting how Microsoft Outlook handles files in memory.

Overview

7.8
CVSS HIGH
Critical
MS Severity
Not Exploited
MS Exploit Status
Less Likely
MS Exploit Likelihood
Category Remote Code Execution
Released Jul 14 2020
Last Updated Jul 14 2020
Publicly Disclosed No
CISA KEV Not Listed
Known Exploits None Known
EPSS Score 0.22501 — 0.97409 percentile
NVD CVSS 7.8 HIGH — differs from MSRC

CVSS Vector

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
ATTACK VECTOR
Local
ATTACK COMPLEXITY
Low
PRIVILEGES REQUIRED
None
USER INTERACTION
Required
SCOPE
Unchanged

EPSS Score

0.22501
probability of exploitation in the next 30 days
0.97409 percentile - updated 2026-06-21
View on FIRST.org

Affected Products

11 affected products
Product KB Article Severity Impact Restart Required
Microsoft 365 Apps for Enterprise for 32-bit Systems Click to Run (Security Update) Critical Remote Code Execution No
Microsoft 365 Apps for Enterprise for 64-bit Systems Click to Run (Security Update) Critical Remote Code Execution No
Microsoft Office 2019 for 32-bit editions Click to Run (Security Update) Critical Remote Code Execution No
Microsoft Office 2019 for 64-bit editions Click to Run (Security Update) Critical Remote Code Execution No
Microsoft Outlook 2010 Service Pack 2 (32-bit editions) 4484382 (Security Update) Critical Remote Code Execution Maybe
Microsoft Outlook 2010 Service Pack 2 (64-bit editions) 4484382 (Security Update) Critical Remote Code Execution Maybe
Microsoft Outlook 2013 RT Service Pack 1 4484363 (Security Update) Critical Remote Code Execution Maybe
Microsoft Outlook 2013 Service Pack 1 (32-bit editions) 4484363 (Security Update) Critical Remote Code Execution Maybe
Microsoft Outlook 2013 Service Pack 1 (64-bit editions) 4484363 (Security Update) Critical Remote Code Execution Maybe
Microsoft Outlook 2016 (32-bit edition) 4484433 (Security Update) Critical Remote Code Execution Maybe
Microsoft Outlook 2016 (64-bit edition) 4484433 (Security Update) Critical Remote Code Execution Maybe

Patches

4 patches
Article Type Restart
Click to Run Security Update No
4484382 Security Update Maybe
4484363 Security Update Maybe
4484433 Security Update Maybe

Known Exploits

Acknowledgments