Critical EPSS 0.17263 2020-01 archive

Executive Summary

A remote code execution vulnerability exists in .NET software when the software fails to check the source markup of a file. An attacker who successfully exploited the vulnerability could run arbitrary code in the context of the current user. If the current user is logged on with administrative user rights, an attacker could take control of the affected system. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights. Users whose accounts are configured to have fewer user rights on the system could be less impacted than users who operate with administrative user rights. Exploitation of the vulnerability requires that a user open a specially crafted file with an affected version of .NET Framework. In an email attack scenario, an attacker could exploit the vulnerability by sending the specially crafted file to the user and convincing the user to open the file. The security update addresses the vulnerability by correcting how .NET Framework checks the source markup of a file.

Overview

Critical
MS Severity
Not Exploited
MS Exploit Status
Less Likely
MS Exploit Likelihood
Category Remote Code Execution
Released Jan 14 2020
Last Updated Jan 14 2020
Publicly Disclosed No
CISA KEV Not Listed
Known Exploits None Known
EPSS Score 0.17263 — 0.96712 percentile

EPSS Score

0.17263
probability of exploitation in the next 30 days
0.96712 percentile - updated 2026-06-20
View on FIRST.org

Affected Products

88 affected products
Product KB Article Severity Impact Restart Required
.NET Core 3.0 Release Notes (Security Update) Critical Remote Code Execution Maybe
.NET Core 3.1 Release Notes (Security Update) Critical Remote Code Execution Maybe
Microsoft .NET Framework 3.0 Service Pack 2 on Windows Server 2008 for 32-bit Systems Service Pack 2 4535105 (Monthly Rollup) 4534979 (Security Only) Critical Remote Code Execution Maybe
Microsoft .NET Framework 3.0 Service Pack 2 on Windows Server 2008 for Itanium-Based Systems Service Pack 2 4535105 (Monthly Rollup) 4534979 (Security Only) Critical Remote Code Execution Maybe
Microsoft .NET Framework 3.0 Service Pack 2 on Windows Server 2008 for x64-based Systems Service Pack 2 4535105 (Monthly Rollup) 4534979 (Security Only) Critical Remote Code Execution Maybe
Microsoft .NET Framework 3.5 AND 4.6.2/4.7/4.7.1/4.7.2 on Windows 10 Version 1607 for 32-bit Systems 4534271 (Security Update) Critical Remote Code Execution Yes
Microsoft .NET Framework 3.5 AND 4.6.2/4.7/4.7.1/4.7.2 on Windows 10 Version 1607 for x64-based Systems 4534271 (Security Update) Critical Remote Code Execution Yes
Microsoft .NET Framework 3.5 AND 4.6.2/4.7/4.7.1/4.7.2 on Windows Server 2016 4534271 (Security Update) Critical Remote Code Execution Yes
Microsoft .NET Framework 3.5 AND 4.6.2/4.7/4.7.1/4.7.2 on Windows Server 2016 (Server Core installation) 4534271 (Security Update) Critical Remote Code Execution Yes
Microsoft .NET Framework 3.5 AND 4.6/4.6.1/4.6.2 on Windows 10 for 32-bit Systems 4534306 (Security Update) Critical Remote Code Execution Yes
Microsoft .NET Framework 3.5 AND 4.6/4.6.1/4.6.2 on Windows 10 for x64-based Systems 4534306 (Security Update) Critical Remote Code Execution Yes
Microsoft .NET Framework 3.5 AND 4.7.1/4.7.2 on Windows 10 Version 1709 for 32-bit Systems 4534276 (Security Update) Critical Remote Code Execution Yes
Microsoft .NET Framework 3.5 AND 4.7.1/4.7.2 on Windows 10 Version 1709 for x64-based Systems 4534276 (Security Update) Critical Remote Code Execution Yes
Microsoft .NET Framework 3.5 AND 4.7.2 on Windows 10 Version 1803 for 32-bit Systems 4534293 (Security Update) Critical Remote Code Execution Yes
Microsoft .NET Framework 3.5 AND 4.7.2 on Windows 10 Version 1803 for x64-based Systems 4534293 (Security Update) Critical Remote Code Execution Yes
Microsoft .NET Framework 3.5 AND 4.7.2 on Windows 10 Version 1809 for 32-bit Systems 4535101 (Security Update) Critical Remote Code Execution Maybe
Microsoft .NET Framework 3.5 AND 4.7.2 on Windows 10 Version 1809 for x64-based Systems 4535101 (Security Update) Critical Remote Code Execution Maybe
Microsoft .NET Framework 3.5 AND 4.7.2 on Windows Server 2019 4535101 (Security Update) Critical Remote Code Execution Maybe
Microsoft .NET Framework 3.5 AND 4.7.2 on Windows Server 2019 (Server Core installation) 4535101 (Security Update) Critical Remote Code Execution Maybe
Microsoft .NET Framework 3.5 AND 4.7.2 on Windows Server, version 1803 (Server Core Installation) 4534293 (Security Update) Critical Remote Code Execution Yes
Microsoft .NET Framework 3.5 AND 4.8 on Windows 10 Version 1809 for 32-bit Systems 4535101 (Security Update) Critical Remote Code Execution Maybe
Microsoft .NET Framework 3.5 AND 4.8 on Windows 10 Version 1809 for x64-based Systems 4535101 (Security Update) Critical Remote Code Execution Maybe
Microsoft .NET Framework 3.5 AND 4.8 on Windows 10 Version 1903 for 32-bit Systems 4532938 (Security Update) Critical Remote Code Execution Maybe
Microsoft .NET Framework 3.5 AND 4.8 on Windows 10 Version 1903 for x64-based Systems 4532938 (Security Update) Critical Remote Code Execution Maybe
Microsoft .NET Framework 3.5 AND 4.8 on Windows 10 Version 1909 for 32-bit Systems 4532938 (Security Update) Critical Remote Code Execution Maybe
Microsoft .NET Framework 3.5 AND 4.8 on Windows 10 Version 1909 for x64-based Systems 4532938 (Security Update) Critical Remote Code Execution Maybe
Microsoft .NET Framework 3.5 AND 4.8 on Windows Server 2019 4535101 (Security Update) Critical Remote Code Execution Maybe
Microsoft .NET Framework 3.5 AND 4.8 on Windows Server 2019 (Server Core installation) 4535101 (Security Update) Critical Remote Code Execution Maybe
Microsoft .NET Framework 3.5 AND 4.8 on Windows Server, version 1903 (Server Core installation) 4532938 (Security Update) Critical Remote Code Execution Maybe
Microsoft .NET Framework 3.5 AND 4.8 on Windows Server, version 1909 (Server Core installation) 4532938 (Security Update) Critical Remote Code Execution Maybe
Microsoft .NET Framework 3.5 on Windows 10 Version 1607 for 32-bit Systems 4534271 (Security Update) Critical Remote Code Execution Yes
Microsoft .NET Framework 3.5 on Windows 8.1 for 32-bit systems 4535104 (Monthly Rollup) 4534978 (Security Only) Critical Remote Code Execution Maybe
Microsoft .NET Framework 3.5 on Windows 8.1 for x64-based systems 4535104 (Monthly Rollup) 4534978 (Security Only) Critical Remote Code Execution Maybe
Microsoft .NET Framework 3.5 on Windows Server 2012 4535103 (Monthly Rollup) 4534977 (Security Only) Critical Remote Code Execution Maybe
Microsoft .NET Framework 3.5 on Windows Server 2012 (Server Core installation) 4535103 (Monthly Rollup) 4534977 (Security Only) Critical Remote Code Execution Maybe
Microsoft .NET Framework 3.5 on Windows Server 2012 R2 4535104 (Monthly Rollup) 4534978 (Security Only) Critical Remote Code Execution Maybe
Microsoft .NET Framework 3.5 on Windows Server 2012 R2 (Server Core installation) 4535104 (Monthly Rollup) 4534978 (Security Only) Critical Remote Code Execution Maybe
Microsoft .NET Framework 3.5.1 on Windows 7 for 32-bit Systems Service Pack 1 4535102 (Monthly Rollup) 4534976 (Security Only) Critical Remote Code Execution Maybe
Microsoft .NET Framework 3.5.1 on Windows 7 for x64-based Systems Service Pack 1 4535102 (Monthly Rollup) 4534976 (Security Only) Critical Remote Code Execution Maybe
Microsoft .NET Framework 3.5.1 on Windows Server 2008 R2 for Itanium-Based Systems Service Pack 1 4535102 (Monthly Rollup) 4534976 (Security Only) Critical Remote Code Execution Maybe
Microsoft .NET Framework 3.5.1 on Windows Server 2008 R2 for x64-based Systems Service Pack 1 4535102 (Monthly Rollup) 4534976 (Security Only) Critical Remote Code Execution Maybe
Microsoft .NET Framework 3.5.1 on Windows Server 2008 R2 for x64-based Systems Service Pack 1 (Server Core installation) 4535102 (Monthly Rollup) 4534976 (Security Only) Critical Remote Code Execution Maybe
Microsoft .NET Framework 4.5.2 on Windows 7 for 32-bit Systems Service Pack 1 4535102 (Monthly Rollup) 4534976 (Security Only) Critical Remote Code Execution Maybe
Microsoft .NET Framework 4.5.2 on Windows 7 for x64-based Systems Service Pack 1 4535102 (Monthly Rollup) 4534976 (Security Only) Critical Remote Code Execution Maybe
Microsoft .NET Framework 4.5.2 on Windows 8.1 for 32-bit systems 4535104 (Monthly Rollup) 4534978 (Security Only) Critical Remote Code Execution Maybe
Microsoft .NET Framework 4.5.2 on Windows 8.1 for x64-based systems 4535104 (Monthly Rollup) 4534978 (Security Only) Critical Remote Code Execution Maybe
Microsoft .NET Framework 4.5.2 on Windows RT 8.1 4535104 (Monthly Rollup) Critical Remote Code Execution Maybe
Microsoft .NET Framework 4.5.2 on Windows Server 2008 for 32-bit Systems Service Pack 2 4535105 (Monthly Rollup) 4534979 (Security Only) Critical Remote Code Execution Maybe
Microsoft .NET Framework 4.5.2 on Windows Server 2008 for x64-based Systems Service Pack 2 4535105 (Monthly Rollup) 4534979 (Security Only) Critical Remote Code Execution Maybe
Microsoft .NET Framework 4.5.2 on Windows Server 2008 R2 for x64-based Systems Service Pack 1 4535102 (Monthly Rollup) 4534976 (Security Only) Critical Remote Code Execution Maybe
Microsoft .NET Framework 4.5.2 on Windows Server 2008 R2 for x64-based Systems Service Pack 1 (Server Core installation) 4535102 (Monthly Rollup) 4534976 (Security Only) Critical Remote Code Execution Maybe
Microsoft .NET Framework 4.5.2 on Windows Server 2012 4535103 (Monthly Rollup) 4534977 (Security Only) Critical Remote Code Execution Maybe
Microsoft .NET Framework 4.5.2 on Windows Server 2012 (Server Core installation) 4535103 (Monthly Rollup) 4534977 (Security Only) Critical Remote Code Execution Maybe
Microsoft .NET Framework 4.5.2 on Windows Server 2012 R2 4535104 (Monthly Rollup) 4534978 (Security Only) Critical Remote Code Execution Maybe
Microsoft .NET Framework 4.5.2 on Windows Server 2012 R2 (Server Core installation) 4535104 (Monthly Rollup) 4534978 (Security Only) Critical Remote Code Execution Maybe
Microsoft .NET Framework 4.6 on Windows Server 2008 for 32-bit Systems Service Pack 2 4535105 (Monthly Rollup) 4534979 (Security Only) Critical Remote Code Execution Maybe
Microsoft .NET Framework 4.6 on Windows Server 2008 for x64-based Systems Service Pack 2 4535105 (Monthly Rollup) 4534979 (Security Only) Critical Remote Code Execution Maybe
Microsoft .NET Framework 4.6/4.6.1/4.6.2/4.7/4.7.1/4.7.2 on Windows 7 for 32-bit Systems Service Pack 1 4535102 (Monthly Rollup) 4534976 (Security Only) Critical Remote Code Execution Maybe
Microsoft .NET Framework 4.6/4.6.1/4.6.2/4.7/4.7.1/4.7.2 on Windows 7 for x64-based Systems Service Pack 1 4535102 (Monthly Rollup) 4534976 (Security Only) Critical Remote Code Execution Maybe
Microsoft .NET Framework 4.6/4.6.1/4.6.2/4.7/4.7.1/4.7.2 on Windows 8.1 for 32-bit systems 4535104 (Monthly Rollup) 4534978 (Security Only) Critical Remote Code Execution Maybe
Microsoft .NET Framework 4.6/4.6.1/4.6.2/4.7/4.7.1/4.7.2 on Windows 8.1 for x64-based systems 4535104 (Monthly Rollup) 4534978 (Security Only) Critical Remote Code Execution Maybe
Microsoft .NET Framework 4.6/4.6.1/4.6.2/4.7/4.7.1/4.7.2 on Windows RT 8.1 4535104 (Monthly Rollup) Critical Remote Code Execution Maybe
Microsoft .NET Framework 4.6/4.6.1/4.6.2/4.7/4.7.1/4.7.2 on Windows Server 2008 R2 for x64-based Systems Service Pack 1 4535102 (Monthly Rollup) 4534976 (Security Only) Critical Remote Code Execution Maybe
Microsoft .NET Framework 4.6/4.6.1/4.6.2/4.7/4.7.1/4.7.2 on Windows Server 2008 R2 for x64-based Systems Service Pack 1 (Server Core installation) 4535102 (Monthly Rollup) 4534976 (Security Only) Critical Remote Code Execution Maybe
Microsoft .NET Framework 4.6/4.6.1/4.6.2/4.7/4.7.1/4.7.2 on Windows Server 2012 4535103 (Monthly Rollup) 4534977 (Security Only) Critical Remote Code Execution Maybe
Microsoft .NET Framework 4.6/4.6.1/4.6.2/4.7/4.7.1/4.7.2 on Windows Server 2012 (Server Core installation) 4535103 (Monthly Rollup) 4534977 (Security Only) Critical Remote Code Execution Maybe
Microsoft .NET Framework 4.6/4.6.1/4.6.2/4.7/4.7.1/4.7.2 on Windows Server 2012 R2 4535104 (Monthly Rollup) 4534978 (Security Only) Critical Remote Code Execution Maybe
Microsoft .NET Framework 4.6/4.6.1/4.6.2/4.7/4.7.1/4.7.2 on Windows Server 2012 R2 (Server Core installation) 4535104 (Monthly Rollup) 4534978 (Security Only) Critical Remote Code Execution Maybe
Microsoft .NET Framework 4.8 on Windows 10 Version 1607 for 32-bit Systems 4532933 (Security Update) Critical Remote Code Execution Maybe
Microsoft .NET Framework 4.8 on Windows 10 Version 1607 for x64-based Systems 4532933 (Security Update) Critical Remote Code Execution Maybe
Microsoft .NET Framework 4.8 on Windows 10 Version 1709 for 32-bit Systems 4532935 (Security Update) Critical Remote Code Execution Maybe
Microsoft .NET Framework 4.8 on Windows 10 Version 1709 for x64-based Systems 4532935 (Security Update) Critical Remote Code Execution Maybe
Microsoft .NET Framework 4.8 on Windows 10 Version 1803 for 32-bit Systems 4532936 (Security Update) Critical Remote Code Execution Maybe
Microsoft .NET Framework 4.8 on Windows 10 Version 1803 for x64-based Systems 4532936 (Security Update) Critical Remote Code Execution Maybe
Microsoft .NET Framework 4.8 on Windows 7 for 32-bit Systems Service Pack 1 4535102 (Monthly Rollup) 4534976 (Security Only) Critical Remote Code Execution Maybe
Microsoft .NET Framework 4.8 on Windows 7 for x64-based Systems Service Pack 1 4535102 (Monthly Rollup) 4534976 (Security Only) Critical Remote Code Execution Maybe
Microsoft .NET Framework 4.8 on Windows 8.1 for 32-bit systems 4535104 (Monthly Rollup) 4534978 (Security Only) Critical Remote Code Execution Maybe
Microsoft .NET Framework 4.8 on Windows 8.1 for x64-based systems 4535104 (Monthly Rollup) 4534978 (Security Only) Critical Remote Code Execution Maybe
Microsoft .NET Framework 4.8 on Windows RT 8.1 4535104 (Monthly Rollup) Critical Remote Code Execution Maybe
Microsoft .NET Framework 4.8 on Windows Server 2008 R2 for x64-based Systems Service Pack 1 4535102 (Monthly Rollup) 4534976 (Security Only) Critical Remote Code Execution Maybe
Microsoft .NET Framework 4.8 on Windows Server 2008 R2 for x64-based Systems Service Pack 1 (Server Core installation) 4535102 (Monthly Rollup) 4534976 (Security Only) Critical Remote Code Execution Maybe
Microsoft .NET Framework 4.8 on Windows Server 2012 4535103 (Monthly Rollup) 4534977 (Security Only) Critical Remote Code Execution Maybe
Microsoft .NET Framework 4.8 on Windows Server 2012 (Server Core installation) 4535103 (Monthly Rollup) 4534977 (Security Only) Critical Remote Code Execution Maybe
Microsoft .NET Framework 4.8 on Windows Server 2012 R2 4535104 (Monthly Rollup) 4534978 (Security Only) Critical Remote Code Execution Maybe
Microsoft .NET Framework 4.8 on Windows Server 2012 R2 (Server Core installation) 4535104 (Monthly Rollup) 4534978 (Security Only) Critical Remote Code Execution Maybe
Microsoft .NET Framework 4.8 on Windows Server 2016 4532933 (Security Update) Critical Remote Code Execution Maybe
Microsoft .NET Framework 4.8 on Windows Server 2016 (Server Core installation) 4532933 (Security Update) Critical Remote Code Execution Maybe
Microsoft .NET Framework 4.8 on Windows Server, version 1803 (Server Core Installation) 4532936 (Security Update) Critical Remote Code Execution Maybe

Patches

15 patches
Article Type Restart
Release Notes Security Update Maybe
4535105 (Monthly Rollup) 4534979 Monthly Rollup Maybe
4534271 Security Update Yes
4534306 Security Update Yes
4534276 Security Update Yes
4534293 Security Update Yes
4535101 Security Update Maybe
4532938 Security Update Maybe
4535104 (Monthly Rollup) 4534978 Monthly Rollup Maybe
4535103 (Monthly Rollup) 4534977 Monthly Rollup Maybe
4535102 (Monthly Rollup) 4534976 Monthly Rollup Maybe
4535104 Monthly Rollup Maybe
4532933 Security Update Maybe
4532935 Security Update Maybe
4532936 Security Update Maybe

Known Exploits

Acknowledgments

@irsdl )