Microsoft Office Access Connectivity Engine Remote Code Execution Vulnerability
Summary
| CVE | CVE-2021-38646 |
|---|---|
| State | PUBLISHED |
| Assigner | microsoft |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2021-09-15 12:15:15 UTC |
| Updated | 2026-08-10 19:59:12 UTC |
| Description | Microsoft Office Access Connectivity Engine Remote Code Execution Vulnerability |
Risk And Classification
Primary CVSS: v3.1 7.8 HIGH from [email protected]
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS: 0.079870000 probability, percentile 0.944050000 (date 2026-08-23)
CISA KEV: Listed on 2022-03-28; due 2022-04-18; ransomware use Known
Problem Types: NVD-CWE-noinfo | Remote Code Execution | CWE-noinfo Not enough information
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Secondary | 7.8 | HIGH | CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H |
| 3.1 | [email protected] | Secondary | 7.8 | HIGH | CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H |
| 3.1 | CNA | CVSS | 7.8 | HIGH | CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C |
| 2.0 | [email protected] | Primary | 6.8 | AV:N/AC:M/Au:N/C:P/I:P/A:P |
CVSS v3.1 Breakdown
Attack Vector
LocalAttack Complexity
LowPrivileges Required
NoneUser Interaction
RequiredScope
UnchangedConfidentiality
HighIntegrity
HighAvailability
HighCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CVSS v2.0 Breakdown
Access Vector
NetworkAccess Complexity
MediumAuthentication
NoneConfidentiality
PartialIntegrity
PartialAvailability
PartialAV:N/AC:M/Au:N/C:P/I:P/A:P
CISA Known Exploited Vulnerability
| Vendor | Microsoft |
|---|---|
| Product | Office |
| Name | Microsoft Office Access Connectivity Engine Remote Code Execution Vulnerability |
| Required Action | Apply updates per vendor instructions. |
| Notes | https://nvd.nist.gov/vuln/detail/CVE-2021-38646 |
NVD Known Affected Configurations (CPE 2.3)
| Type | Vendor | Product | Version | Update | Edition | Language |
|---|---|---|---|---|---|---|
| Application | Microsoft | 365 Apps | - | All | All | All |
| Application | Microsoft | Office | 2013 | sp1 | All | All |
| Application | Microsoft | Office | 2013 | sp1 | All | All |
| Application | Microsoft | Office 2016 | - | All | All | All |
| Application | Microsoft | Office 2016 | - | All | All | All |
| Application | Microsoft | Office 2019 | - | All | All | All |
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Microsoft | Microsoft 365 Apps For Enterprise | affected 16.0.1 https://aka.ms/OfficeSecurityReleases custom | 32-bit Systems, x64-based Systems |
| CNA | Microsoft | Microsoft Office 2013 Service Pack 1 | affected 15.0.0 5381.1000 custom | 32-bit Systems, ARM64-based Systems, x64-based Systems |
| CNA | Microsoft | Microsoft Office 2016 | affected 16.0.0 5215.1000 custom | 32-bit Systems, x64-based Systems |
| CNA | Microsoft | Microsoft Office 2019 | affected 19.0.0 https://aka.ms/OfficeSecurityReleases custom | 32-bit Systems, x64-based Systems |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| msrc.microsoft.com/update-guide/vulnerability/CVE-2021-38646 | [email protected] | msrc.microsoft.com | Patch, Vendor Advisory |
| Security Update Guide - Microsoft Security Response Center | af854a3a-2127-422b-91ae-364da2661108 | portal.msrc.microsoft.com | Patch, Vendor Advisory |
| www.cisa.gov/known-exploited-vulnerabilities-catalog | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | www.cisa.gov | US Government Resource |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
| CISA Known Exploited Vulnerabilities catalog | CISA | www.cisa.gov | kev |
No vendor comments have been submitted for this CVE.
Additional Advisory Data
| Source | Time | Event |
|---|---|---|
| ADP | 2022-03-28T00:00:00.000Z | CVE-2021-38646 added to CISA KEV |
Legacy QID Mappings
- 110390 Microsoft Office and Microsoft Office Services and Web Apps Security Update September 2021