CVE-2020-1056 — Microsoft Edge Elevation of Privilege Vulnerability

Executive Summary

An elevation of privilege vulnerability exists when Microsoft Edge does not properly enforce cross-domain policies, which could allow an attacker to access information from one domain and inject it into another domain. In a web-based attack scenario, an attacker could host a website that is used to attempt to exploit the vulnerability. In addition, compromised websites and websites that accept or host user-provided content could contain specially crafted content that could exploit the vulnerability. However, in all cases an attacker would have no way to force users to view the attacker-controlled content. Instead, an attacker would have to convince users to take action. For example, an attacker could trick users into clicking a link that takes them to the attacker's site. An attacker who successfully exploited this vulnerability could elevate privileges in affected versions of Microsoft Edge. The security update addresses the vulnerability by helping to ensure that cross-domain policies are properly enforced in Microsoft Edge.

Overview

8.1

CVSS HIGH

Critical

MS Severity

Not Exploited

MS Exploit Status

Less Likely

MS Exploit Likelihood

Category Elevation of Privilege

Released May 12 2020

Last Updated May 12 2020

Publicly Disclosed No

CISA KEV Not Listed

Known Exploits None Known

EPSS Score 0.03291 — 0.86888 percentile

NVD CVSS 8.1 HIGH — differs from MSRC

CVSS Vector

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

ATTACK VECTOR

Network

ATTACK COMPLEXITY

Low

PRIVILEGES REQUIRED

None

USER INTERACTION

Required

SCOPE

Unchanged

CONFIDENTIALITY

Low

INTEGRITY

Low

AVAILABILITY

None

EXPLOIT CODE MATURITY

Proof-of-Concept

REMEDIATION LEVEL

Official Fix

REPORT CONFIDENCE

Confirmed

Temporal Score: 4.9

EPSS Score

0.03291

probability of exploitation in the next 30 days

0.86888 percentile - updated 2026-06-21

View on FIRST.org

Affected Products

19 affected products

Product	KB Article	Severity	Impact	Restart Required
Microsoft Edge (EdgeHTML-based) on Windows 10 Version 1607 for 32-bit Systems	`4556813 (Security Update)`	Critical	Elevation of Privilege	Yes
Microsoft Edge (EdgeHTML-based) on Windows 10 Version 1607 for x64-based Systems	`4556813 (Security Update)`	Critical	Elevation of Privilege	Yes
Microsoft Edge (EdgeHTML-based) on Windows 10 Version 1709 for 32-bit Systems	`4556812 (Security Update)`	Critical	Elevation of Privilege	Yes
Microsoft Edge (EdgeHTML-based) on Windows 10 Version 1709 for ARM64-based Systems	`4556812 (Security Update)`	Critical	Elevation of Privilege	Yes
Microsoft Edge (EdgeHTML-based) on Windows 10 Version 1709 for x64-based Systems	`4556812 (Security Update)`	Critical	Elevation of Privilege	Yes
Microsoft Edge (EdgeHTML-based) on Windows 10 Version 1803 for 32-bit Systems	`4556807 (Security Update)`	Critical	Elevation of Privilege	Yes
Microsoft Edge (EdgeHTML-based) on Windows 10 Version 1803 for ARM64-based Systems	`4556807 (Security Update)`	Critical	Elevation of Privilege	Yes
Microsoft Edge (EdgeHTML-based) on Windows 10 Version 1803 for x64-based Systems	`4556807 (Security Update)`	Critical	Elevation of Privilege	Yes
Microsoft Edge (EdgeHTML-based) on Windows 10 Version 1809 for 32-bit Systems	`4551853 (Security Update)`	Critical	Elevation of Privilege	Yes
Microsoft Edge (EdgeHTML-based) on Windows 10 Version 1809 for ARM64-based Systems	`4551853 (Security Update)`	Critical	Elevation of Privilege	Yes
Microsoft Edge (EdgeHTML-based) on Windows 10 Version 1809 for x64-based Systems	`4551853 (Security Update)`	Critical	Elevation of Privilege	Yes
Microsoft Edge (EdgeHTML-based) on Windows 10 Version 1903 for 32-bit Systems	`4556799 (Security Update)`	Critical	Elevation of Privilege	Yes
Microsoft Edge (EdgeHTML-based) on Windows 10 Version 1903 for ARM64-based Systems	`4556799 (Security Update)`	Critical	Elevation of Privilege	Yes
Microsoft Edge (EdgeHTML-based) on Windows 10 Version 1903 for x64-based Systems	`4556799 (Security Update)`	Critical	Elevation of Privilege	Yes
Microsoft Edge (EdgeHTML-based) on Windows 10 Version 1909 for 32-bit Systems	`4556799 (Security Update)`	Critical	Elevation of Privilege	Yes
Microsoft Edge (EdgeHTML-based) on Windows 10 Version 1909 for ARM64-based Systems	`4556799 (Security Update)`	Critical	Elevation of Privilege	Yes
Microsoft Edge (EdgeHTML-based) on Windows 10 Version 1909 for x64-based Systems	`4556799 (Security Update)`	Critical	Elevation of Privilege	Yes
Microsoft Edge (EdgeHTML-based) on Windows Server 2016	`4556813 (Security Update)`	Moderate	Elevation of Privilege	Yes
Microsoft Edge (EdgeHTML-based) on Windows Server 2019	`4551853 (Security Update)`	Moderate	Elevation of Privilege	Yes

Patches

5 patches

Article	Type	Restart
`4556813`	Security Update	Yes
`4556812`	Security Update	Yes
`4556807`	Security Update	Yes
`4551853`	Security Update	Yes
`4556799`	Security Update	Yes

Known Exploits

No known exploits have been linked for this CVE yet. When available, exploit references will be sourced from public repositories and may be unverified, incomplete, or non-functional. Always review code carefully before use in any environment.

Acknowledgments

Qihoo 360 Vulcan Team via Tianfu Cup 2019

References

MSRC Advisory MITRE NVD