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Microsoft Office Excel

CVE-2021-28449 — Microsoft Office Remote Code Execution Vulnerability

Important CVSS 7.8 EPSS 0.02471 2021-04 archive

Executive Summary

None

Overview

7.8
CVSS HIGH
Important
MS Severity
Not Exploited
MS Exploit Status
Less Likely
MS Exploit Likelihood
Category Remote Code Execution
Released Apr 13 2021
Last Updated Apr 13 2021
Publicly Disclosed No
CISA KEV Not Listed
Known Exploits None Known
EPSS Score 0.02471 — 0.82429 percentile
NVD CVSS 7.8 HIGH — matches MSRC

CVSS Vector

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C
ATTACK VECTOR
Local
ATTACK COMPLEXITY
Low
PRIVILEGES REQUIRED
None
USER INTERACTION
Required
SCOPE
Unchanged
CONFIDENTIALITY
High
INTEGRITY
High
AVAILABILITY
High
EXPLOIT CODE MATURITY
Proof-of-Concept
REMEDIATION LEVEL
Official Fix
REPORT CONFIDENCE
Confirmed
Temporal Score: 7.0

EPSS Score

0.02471
probability of exploitation in the next 30 days
0.82429 percentile - updated 2026-06-21
View on FIRST.org

Affected Products

14 affected products
Product KB Article Severity Impact Restart Required
Microsoft 365 Apps for Enterprise for 32-bit Systems Click to Run (Security Update) Important Remote Code Execution No
Microsoft 365 Apps for Enterprise for 64-bit Systems Click to Run (Security Update) Important Remote Code Execution No
Microsoft Excel 2010 Service Pack 2 (32-bit editions) 3017810 (Security Update) Important Remote Code Execution Maybe
Microsoft Excel 2010 Service Pack 2 (64-bit editions) 3017810 (Security Update) Important Remote Code Execution Maybe
Microsoft Excel 2013 RT Service Pack 1 4504735 (Security Update) Important Remote Code Execution Maybe
Microsoft Excel 2013 Service Pack 1 (32-bit editions) 4504735 (Security Update) Important Remote Code Execution Maybe
Microsoft Excel 2013 Service Pack 1 (64-bit editions) 4504735 (Security Update) Important Remote Code Execution Maybe
Microsoft Excel 2016 (32-bit edition) 4504721 (Security Update) Important Remote Code Execution Maybe
Microsoft Excel 2016 (64-bit edition) 4504721 (Security Update) Important Remote Code Execution Maybe
Microsoft Office 2010 Service Pack 2 (32-bit editions) 2553491 (Security Update) 2589361 (Security Update) 4504738 (Security Update) Important Remote Code Execution 4504703 Base: 7.8 Temporal: 7.0 Vector: CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C Maybe None Microsoft Office 2010 Service Pack 2 (64-bit editions) 2553491 (Security Update) 2589361 (Security Update) 4504738 (Security Update) Important Remote Code Execution 4504703 Base: 7.8 Temporal: 7.0 Vector: CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C Maybe None Microsoft Office 2013 RT Service Pack 1 4504726 (Security Update) Important Remote Code Execution Maybe
Microsoft Office 2013 Service Pack 1 (32-bit editions) 4504726 (Security Update) 3178643 (Security Update) 3178639 (Security Update) Important Remote Code Execution 4493228 Base: 7.8 Temporal: 7.0 Vector: CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C Maybe 4504726 Microsoft Office 2013 Service Pack 1 (64-bit editions) 4504726 (Security Update) 3178643 (Security Update) 3178639 (Security Update) Important Remote Code Execution 4493228 Base: 7.8 Temporal: 7.0 Vector: CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C Maybe 4504726 Microsoft Office 2016 (32-bit edition) 4504722 (Security Update) Important Remote Code Execution Maybe
Microsoft Office 2016 (64-bit edition) 4504722 (Security Update) Important Remote Code Execution Maybe
Microsoft Office 2019 for 32-bit editions Click to Run (Security Update) Important Remote Code Execution No
Microsoft Office 2019 for 64-bit editions Click to Run (Security Update) Important Remote Code Execution No

Patches

6 patches
Article Type Restart
Click to Run Security Update No
3017810 Security Update Maybe
4504735 Security Update Maybe
4504721 Security Update Maybe
4504726 Security Update Maybe
4504722 Security Update Maybe

Known Exploits

Acknowledgments

Dima van de Wouw, Nathan Shomber of Microsoft

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