CVE-2020-1147 Microsoft .NET Framework, SharePoint, and Visual Studio Remote Code Execution

Exploited in the wild High 7.8 Published Updated

Remote attackers can execute arbitrary code by exploiting an XML External Entity vulnerability in .NET Framework, SharePoint, and Visual Studio.

Exploited in the wild
Since 3 Nov 2021
Login needed
Not needed
Attackable
Local or same network only
Victim action needed
A user has to click or open something
Fix
Available

What is CVE-2020-1147?

CVE-2020-1147 is a high-severity vulnerability in Microsoft .Net Framework, published on 14 Jul 2020. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

Official description

A remote code execution vulnerability exists in .NET Framework, Microsoft SharePoint, and Visual Studio when the software fails to check the source markup of XML file input, aka '.NET Framework, SharePoint Server, and Visual Studio Remote Code Execution Vulnerability'.

Which versions are affected by CVE-2020-1147?

24 open source packages ship an affected version, including Microsoft.NETCore.App, Microsoft.NETCore.App.Runtime.linux-arm and Microsoft.NETCore.App.Runtime.linux-arm64. It affects 6 products.

PackageAffectedFixed in
Microsoft.NETCore.App NuGetFrom 2.1.02.1.20
Microsoft.NETCore.App NuGetFrom 2.1.02.1.20
Microsoft.NETCore.App.Runtime.linux-arm NuGetFrom 3.1.03.1.6
Microsoft.NETCore.App.Runtime.linux-arm NuGetFrom 3.1.03.1.6
Microsoft.NETCore.App.Runtime.linux-arm64 NuGetFrom 3.1.03.1.6
Microsoft.NETCore.App.Runtime.linux-arm64 NuGetFrom 3.1.03.1.6
18 more packages
Microsoft.NETCore.App.Runtime.linux-musl-arm64 NuGetFrom 3.1.03.1.6
Microsoft.NETCore.App.Runtime.linux-musl-arm64 NuGetFrom 3.1.03.1.6
Microsoft.NETCore.App.Runtime.linux-musl-x64 NuGetFrom 3.1.03.1.6
Microsoft.NETCore.App.Runtime.linux-musl-x64 NuGetFrom 3.1.03.1.6
Microsoft.NETCore.App.Runtime.linux-x64 NuGetFrom 3.1.03.1.6
Microsoft.NETCore.App.Runtime.linux-x64 NuGetFrom 3.1.03.1.6
Microsoft.NETCore.App.Runtime.osx-x64 NuGetFrom 3.1.03.1.6
Microsoft.NETCore.App.Runtime.osx-x64 NuGetFrom 3.1.03.1.6
Microsoft.NETCore.App.Runtime.rhel.6-x64 NuGetFrom 3.1.03.1.6
Microsoft.NETCore.App.Runtime.rhel.6-x64 NuGetFrom 3.1.03.1.6
Microsoft.NETCore.App.Runtime.win-arm NuGetFrom 3.1.03.1.6
Microsoft.NETCore.App.Runtime.win-arm NuGetFrom 3.1.03.1.6
Microsoft.NETCore.App.Runtime.win-arm64 NuGetFrom 3.1.03.1.6
Microsoft.NETCore.App.Runtime.win-arm64 NuGetFrom 3.1.03.1.6
Microsoft.NETCore.App.Runtime.win-x64 NuGetFrom 3.1.03.1.6
Microsoft.NETCore.App.Runtime.win-x64 NuGetFrom 3.1.03.1.6
Microsoft.NETCore.App.Runtime.win-x86 NuGetFrom 3.1.03.1.6
Microsoft.NETCore.App.Runtime.win-x86 NuGetFrom 3.1.03.1.6
Linux distribution packages (16)
aspnetcore-runtime-3.1 Red Hat:enterprise_linux:8::appstreamAll versions0:3.1.6-1.el8_2
aspnetcore-targeting-pack-3.1 Red Hat:enterprise_linux:8::appstreamAll versions0:3.1.6-1.el8_2
dotnet Red Hat:enterprise_linux:8::appstreamAll versions0:2.1.516-1.el8_2
dotnet Red Hat:enterprise_linux:8::appstreamAll versions0:3.1.106-1.el8_2
dotnet-apphost-pack-3.1 Red Hat:enterprise_linux:8::appstreamAll versions0:3.1.6-1.el8_2
dotnet-apphost-pack-3.1-debuginfo Red Hat:enterprise_linux:8::appstreamAll versions0:3.1.6-1.el8_2
dotnet-debuginfo Red Hat:enterprise_linux:8::appstreamAll versions0:2.1.516-1.el8_2
dotnet-debugsource Red Hat:enterprise_linux:8::appstreamAll versions0:2.1.516-1.el8_2
dotnet-host Red Hat:enterprise_linux:8::appstreamAll versions0:3.1.6-1.el8_2
dotnet-host-debuginfo Red Hat:enterprise_linux:8::appstreamAll versions0:3.1.6-1.el8_2
dotnet-host-fxr-2.1 Red Hat:enterprise_linux:8::appstreamAll versions0:2.1.20-1.el8_2
dotnet-host-fxr-2.1-debuginfo Red Hat:enterprise_linux:8::appstreamAll versions0:2.1.20-1.el8_2
dotnet-hostfxr-3.1 Red Hat:enterprise_linux:8::appstreamAll versions0:3.1.6-1.el8_2
dotnet-hostfxr-3.1-debuginfo Red Hat:enterprise_linux:8::appstreamAll versions0:3.1.6-1.el8_2
dotnet-runtime-2.1 Red Hat:enterprise_linux:8::appstreamAll versions0:2.1.20-1.el8_2
dotnet-runtime-2.1-debuginfo Red Hat:enterprise_linux:8::appstreamAll versions0:2.1.20-1.el8_2

Products include Microsoft .Net Core, Microsoft .Net Framework, Microsoft Sharepoint Enterprise Server, Microsoft Sharepoint Server, Microsoft Visual Studio 2017, Microsoft Visual Studio 2019.

How do I fix CVE-2020-1147?

Upgrade Microsoft.NETCore.App to 2.1.20 or later. US federal agencies must fix it by 3 May 2022.

Is CVE-2020-1147 being exploited?

Yes. Attackers have exploited CVE-2020-1147 in the wild since at least 3 Nov 2021.

Public exploit code: 1 Metasploit module and 2 Exploit-DB entries.

All Microsoft .Net Framework vulnerabilities

Sources

Also known as GHSA-g5vf-38cp-4px9, RHSA-2020:2937, RHSA-2020:2938, RHSA-2020:2939, RHSA-2020:2954, RHSA-2020:2988 and 1 more.

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