CVE-2020-16952 — Microsoft SharePoint Remote Code Execution Vulnerability

Executive Summary

A remote code execution vulnerability exists in Microsoft SharePoint when the software fails to check the source markup of an application package. An attacker who successfully exploited the vulnerability could run arbitrary code in the context of the SharePoint application pool and the SharePoint server farm account. Exploitation of this vulnerability requires that a user uploads a specially crafted SharePoint application package to an affected version of SharePoint. The security update addresses the vulnerability by correcting how SharePoint checks the source markup of application packages.

Overview

8.6

CVSS HIGH

Critical

MS Severity

Not Exploited

MS Exploit Status

Less Likely

MS Exploit Likelihood

Category Remote Code Execution

Released Oct 13 2020

Last Updated Oct 13 2020

Publicly Disclosed No

CISA KEV Not Listed

Known Exploits None Known

EPSS Score 0.71095 — 0.99351 percentile

NVD CVSS 8.6 HIGH — matches MSRC

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:L/E:P/RL:O/RC:C

ATTACK VECTOR

Network

ATTACK COMPLEXITY

Low

PRIVILEGES REQUIRED

None

USER INTERACTION

None

SCOPE

Unchanged

CONFIDENTIALITY

Low

INTEGRITY

High

AVAILABILITY

Low

EXPLOIT CODE MATURITY

Proof-of-Concept

REMEDIATION LEVEL

Official Fix

REPORT CONFIDENCE

Confirmed

Temporal Score: 7.7

EPSS Score

0.71095

probability of exploitation in the next 30 days

0.99351 percentile - updated 2026-08-14

View on FIRST.org

Affected Products

3 affected products

Product	KB Article	Severity	Impact	Restart Required
Microsoft SharePoint Enterprise Server 2016	`4486677 (Security Update)`	Critical	Remote Code Execution	Maybe
Microsoft SharePoint Foundation 2013 Service Pack 1	`4486694 (Security Update)`	Critical	Remote Code Execution	Maybe
Microsoft SharePoint Server 2019	`4486676 (Security Update)`	Critical	Remote Code Execution	Maybe

Patches

3 patches

Article	Type	Restart
`4486677`	Security Update	Maybe
`4486694`	Security Update	Maybe
`4486676`	Security Update	Maybe

Exploits & PoC

No public exploit or PoC has been linked for this CVE yet. When available, references are sourced from public repositories and may be unverified or non-functional — review carefully before use.

Detection Rules

Detection available

Community detection & vulnerability-scanning rules aggregated from Sigma and Nuclei templates. Validate and tune to your environment before deploying.

Nuclei templates 1

CVE-2020-16952 Microsoft SharePoint - Remote Code Execution high

nuclei -id CVE-2020-16952

Acknowledgments

Steven Seeley (mr_me)

References

MSRC Advisory MITRE NVD