CVE-2020-0646 — .NET Framework Remote Code Execution Injection Vulnerability

Critical CVSS 9.8 EPSS 0.99222 2020-01 archive

Executive Summary

A remote code execution vulnerability exists when the Microsoft .NET Framework fails to validate input properly. An attacker who successfully exploited this vulnerability could take control of an 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. To exploit the vulnerability, an attacker would need to pass specific input to an application utilizing susceptible .Net methods. The security update addresses the vulnerability by correcting how the Microsoft .NET Framework validates input.

Overview

9.8

CVSS CRITICAL

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 0.99222 — 0.99932 percentile

NVD CVSS 9.8 CRITICAL — differs from MSRC

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

ATTACK VECTOR

Network

ATTACK COMPLEXITY

Low

PRIVILEGES REQUIRED

None

USER INTERACTION

None

SCOPE

Unchanged

EPSS Score

0.99222

probability of exploitation in the next 30 days

0.99932 percentile - updated 2026-07-25

View on FIRST.org

Affected Products

39 affected products

Product	KB Article	Severity	Impact	Restart Required
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 4524744; 4533098 Base: N/A Temporal: N/A Vector: N/A Maybe None 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 4524744; 4533098 Base: N/A Temporal: N/A Vector: N/A Maybe None 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 4524744; 4533098 Base: N/A Temporal: N/A Vector: N/A Maybe None 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 4524743; 4533097 Base: N/A Temporal: N/A Vector: N/A Maybe None Microsoft .NET Framework 3.5 on Windows 8.1 for x64-based systems 4535104 (Monthly Rollup) 4534978 (Security Only) Critical Remote Code Execution 4524743; 4533097 Base: N/A Temporal: N/A Vector: N/A Maybe None Microsoft .NET Framework 3.5 on Windows Server 2012 4535103 (Monthly Rollup) 4534977 (Security Only) Critical Remote Code Execution 4524742; 4533096 Base: N/A Temporal: N/A Vector: N/A Maybe None Microsoft .NET Framework 3.5 on Windows Server 2012 (Server Core installation) 4535103 (Monthly Rollup) 4534977 (Security Only) Critical Remote Code Execution 4524742; 4533096 Base: N/A Temporal: N/A Vector: N/A Maybe None Microsoft .NET Framework 3.5 on Windows Server 2012 R2 4535104 (Monthly Rollup) 4534978 (Security Only) Critical Remote Code Execution 4524743; 4533097 Base: N/A Temporal: N/A Vector: N/A Maybe None Microsoft .NET Framework 3.5 on Windows Server 2012 R2 (Server Core installation) 4535104 (Monthly Rollup) 4534978 (Security Only) Critical Remote Code Execution 4524743; 4533097 Base: N/A Temporal: N/A Vector: N/A Maybe None 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 4524741; 4533095 Base: N/A Temporal: N/A Vector: N/A Maybe None 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 4524741; 4533095 Base: N/A Temporal: N/A Vector: N/A Maybe None 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 4524741; 4533095 Base: N/A Temporal: N/A Vector: N/A Maybe None 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 4524741; 4533095 Base: N/A Temporal: N/A Vector: N/A Maybe None 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 4524741; 4533095 Base: N/A Temporal: N/A Vector: N/A Maybe None 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 4524741; 4533095 Base: N/A Temporal: N/A Vector: N/A Maybe None 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 4524741; 4533095 Base: N/A Temporal: N/A Vector: N/A Maybe None Microsoft .NET Framework 4.5.2 on Windows 8.1 for 32-bit systems 4535104 (Monthly Rollup) 4534978 (Security Only) Critical Remote Code Execution 4524743; 4533097 Base: N/A Temporal: N/A Vector: N/A Maybe None Microsoft .NET Framework 4.5.2 on Windows 8.1 for x64-based systems 4535104 (Monthly Rollup) 4534978 (Security Only) Critical Remote Code Execution 4524743; 4533097 Base: N/A Temporal: N/A Vector: N/A Maybe None 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 4524744; 4533098 Base: N/A Temporal: N/A Vector: N/A Maybe None 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 4524744; 4533098 Base: N/A Temporal: N/A Vector: N/A Maybe None 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 4524741; 4533095 Base: N/A Temporal: N/A Vector: N/A Maybe None 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 4524741; 4533095 Base: N/A Temporal: N/A Vector: N/A Maybe None Microsoft .NET Framework 4.5.2 on Windows Server 2012 4535103 (Monthly Rollup) 4534977 (Security Only) Critical Remote Code Execution 4524742; 4533096 Base: N/A Temporal: N/A Vector: N/A Maybe None Microsoft .NET Framework 4.5.2 on Windows Server 2012 (Server Core installation) 4535103 (Monthly Rollup) 4534977 (Security Only) Critical Remote Code Execution 4524742; 4533096 Base: N/A Temporal: N/A Vector: N/A Maybe None Microsoft .NET Framework 4.5.2 on Windows Server 2012 R2 4535104 (Monthly Rollup) 4534978 (Security Only) Critical Remote Code Execution 4524743; 4533097 Base: N/A Temporal: N/A Vector: N/A Maybe None Microsoft .NET Framework 4.5.2 on Windows Server 2012 R2 (Server Core installation) 4535104 (Monthly Rollup) 4534978 (Security Only) Critical Remote Code Execution 4524743; 4533097 Base: N/A Temporal: N/A Vector: N/A Maybe None 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 Base: N/A Temporal: N/A Vector: N/A Maybe None 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 Base: N/A Temporal: N/A Vector: N/A Maybe None Microsoft .NET Framework 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 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 4524741; 4533095 Base: N/A Temporal: N/A Vector: N/A Maybe None 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 4524741; 4533095 Base: N/A Temporal: N/A Vector: N/A Maybe None 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 4524743; 4533097 Base: N/A Temporal: N/A Vector: N/A Maybe None 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 4524743; 4533097 Base: N/A Temporal: N/A Vector: N/A Maybe None 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 4524741; 4533095 Base: N/A Temporal: N/A Vector: N/A Maybe None 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 4524741; 4533095 Base: N/A Temporal: N/A Vector: N/A Maybe None 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 4524742; 4533096 Base: N/A Temporal: N/A Vector: N/A Maybe None 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 4524742; 4533096 Base: N/A Temporal: N/A Vector: N/A Maybe None 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 4524743; 4533097 Base: N/A Temporal: N/A Vector: N/A Maybe None 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 4524743; 4533097 Base: N/A Temporal: N/A Vector: N/A Maybe None 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 Base: N/A Temporal: N/A Vector: N/A Maybe None 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 Base: N/A Temporal: N/A Vector: N/A Maybe None Microsoft .NET Framework 4.8 on Windows 8.1 for 32-bit systems 4535104 (Monthly Rollup) 4534978 (Security Only) Critical Remote Code Execution Base: N/A Temporal: N/A Vector: N/A Maybe None Microsoft .NET Framework 4.8 on Windows 8.1 for x64-based systems 4535104 (Monthly Rollup) 4534978 (Security Only) Critical Remote Code Execution Base: N/A Temporal: N/A Vector: N/A Maybe None 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 Base: N/A Temporal: N/A Vector: N/A Maybe None 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 Base: N/A Temporal: N/A Vector: N/A Maybe None Microsoft .NET Framework 4.8 on Windows Server 2012 4535103 (Monthly Rollup) 4534977 (Security Only) Critical Remote Code Execution Base: N/A Temporal: N/A Vector: N/A Maybe None Microsoft .NET Framework 4.8 on Windows Server 2012 (Server Core installation) 4535103 (Monthly Rollup) 4534977 (Security Only) Critical Remote Code Execution Base: N/A Temporal: N/A Vector: N/A Maybe None Microsoft .NET Framework 4.8 on Windows Server 2012 R2 4535104 (Monthly Rollup) 4534978 (Security Only) Critical Remote Code Execution Base: N/A Temporal: N/A Vector: N/A Maybe None Microsoft .NET Framework 4.8 on Windows Server 2012 R2 (Server Core installation) 4535104 (Monthly Rollup) 4534978 (Security Only) Critical Remote Code Execution Base: N/A Temporal: N/A Vector: N/A Maybe None 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

10 patches

Article	Type	Restart
`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	Maybe
`4532933`	Security Update	Maybe
`4532935`	Security Update	Maybe
`4532936`	Security Update	Maybe

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

Soroush Dalili ( @irsdl

References

MSRC Advisory MITRE NVD

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