Important CVSS 4.7 EPSS 0.04006 2020-09 archive

Executive Summary

A spoofing vulnerability manifests in Microsoft Xamarin.Forms due to the default settings on Android WebView version prior to 83.0.4103.106. This vulnerability could allow an attacker to execute arbitrary Javascript code on a target system. For the attack to be successful, the targeted user would need to browse to a malicious website or a website serving the malicious code through Xamarin.Forms. The security update addresses this vulnerability by preventing the malicious Javascript from running in the WebView.

Overview

4.7
CVSS MEDIUM
Important
MS Severity
Not Exploited
MS Exploit Status
Less Likely
MS Exploit Likelihood
Category Spoofing
Released Sep 8 2020
Last Updated Sep 8 2020
Publicly Disclosed No
CISA KEV Not Listed
Known Exploits None Known
EPSS Score 0.04006 — 0.8922 percentile
NVD CVSS 4.7 MEDIUM — matches MSRC

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:N/A:N/E:F/RL:O/RC:C
ATTACK VECTOR
Network
ATTACK COMPLEXITY
Low
PRIVILEGES REQUIRED
None
USER INTERACTION
Required
SCOPE
Changed
CONFIDENTIALITY
Low
INTEGRITY
None
AVAILABILITY
None
EXPLOIT CODE MATURITY
Functional
REMEDIATION LEVEL
Official Fix
REPORT CONFIDENCE
Confirmed
Temporal Score: 4.4

EPSS Score

0.04006
probability of exploitation in the next 30 days
0.8922 percentile - updated 2026-06-21
View on FIRST.org

Affected Products

1 affected product
Product KB Article Severity Impact Restart Required
xamarin.forms Release Notes (Security Update) Important Spoofing Maybe

Patches

1 patch
Article Type Restart
Release Notes Security Update Maybe

Known Exploits

Acknowledgments