CVE-2021-27059 | Microsoft Office Remote Code Execution Vulnerability

Exp

Microsoft Office Remote Code Execution Vulnerability

Published: 2021-03-11 Last update: 2025-10-30 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-27059 is rated Critical Active Threat (85.3/100): CVSS High severity, with medium exploitation likelihood (EPSS 2.76%). CISA KEV confirms active exploitation (added 2021-11-03) affecting Microsoft / Office. Unauthenticated remote administrative access may be possible. The CISA remediation deadline has passed—treat as an emergency patch priority.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

CISA KEV Record for CVE-2021-27059

Name: Microsoft Office Remote Code Execution Vulnerability · CISA KEV detail

Exploit added: 2021-11-03

Action due: 2021-11-17

Required action: Apply updates per vendor instructions.

Exploit prediction scoring system (EPSS) score for CVE-2021-27059

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-08 2.97% 2.76% -0.20%
2 2026-03-20 2.04% 2.97% +0.92%
3 2026-01-30 — 2.04% —

Full EPSS history (35 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-27059

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.6 3.1 HIGH
CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:C/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:H)
They need powerful rights—admin, root, or similar—before this pays off.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.0 6.0 [email protected]
6.5 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:H)
They need powerful rights—admin, root, or similar—before this pays off.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 0.6 5.9 [email protected]
8.5 2.0 HIGH
AV:N/AC:M/Au:S/C:C/I:C/A:C Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:S)
A single authentication is required.
Confidentiality impact (C:C)
Complete confidentiality impact.
Integrity impact (I:C)
Complete integrity impact.
Availability impact (A:C)
Complete availability impact.
 6.8 10.0 [email protected]

Weakness enumeration for CVE-2021-27059

Affected software / configurations for CVE-2021-27059

Vendor Product Version Raw CPE
microsoft office 2010 cpe:2.3:a:microsoft:office:2010:sp2:*:*:*:*:*:*
microsoft office 2013 cpe:2.3:a:microsoft:office:2013:sp1:*:*:*:*:*:*
microsoft office 2013 cpe:2.3:a:microsoft:office:2013:sp1:*:*:rt:*:*:*
microsoft office 2016 cpe:2.3:a:microsoft:office:2016:*:*:*:*:*:*:*

References for CVE-2021-27059

cvelogic Threat Intelligence