CVE-2020-1147 KEVPublic exploit High · 7.8 EPSS 95.8%
Microsoft .NET Framework, SharePoint, and Visual Studio Remote Code Execution Vulnerability
Microsoft · .NET Framework, SharePoint, Visual Studio
Official description · NVD
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'.
Priority scorePatchfirst’s 0 to 100 ranking. It adds points for CISA KEV listing, ransomware use, EPSS, threat reports, public exploit code and CVSS. Every CVE page shows the breakdown. Breakdown
68.4 / 100
- Exploited
- Yes, in CISA KEV
- Reports
- 0
- Tactics
- 1/15
How an attack unfolds
Based on MITRE ATT&CKA public catalogue of the techniques attackers use, maintained by MITRE. Patchfirst uses it to describe what attackers do with a vulnerability. mappings. Select a step to see the evidence.How attackers get in
What they do
Exploitation timelineDated milestones for a CVE: when it was disclosed, when exploit code became public, when exploitation was confirmed, and when threat reports named it.
First seen exploited 16 months after disclosure. Public exploit code (Metasploit) was available the same day.
CISA KEV listing is when exploitation was confirmed, not necessarily the first attack.
Patch historyEarlier and later CVEs in the same code, in date order. It shows when a fix was bypassed or incomplete and which version finally fixed it.
7 fixes in Microsoft.NETCore.App over 4 years. The latest fix listed for Microsoft.NETCore.App is 2.2.1.
Fixes in Microsoft.NETCore.AppNuGet package, by fixed version. Earlier and later fixes in the same package, not necessarily the same bug.
- 2.0.3CVE-2017-1177015 Nov 2017
- 2.1.7CVE-2018-841614 Nov 2018
- 2.1.18CVE-2020-110821 May 2020
- 2.1.20CVE-2020-114714 Jul 2020KEV
- 2.1.25CVE-2021-172125 Feb 2021
- 2.1.29CVE-2021-3448512 Aug 2021
- 2.2.1CVE-2019-05458 Jan 2019Latest listed
MITRE ATT&CKA public catalogue of the techniques attackers use, maintained by MITRE. Patchfirst uses it to describe what attackers do with a vulnerability. techniques
2 TechniqueOne specific attacker behaviour in MITRE ATT&CK, such as T1190 “Exploit Public-Facing Application”. IDs with a dot, like T1059.004, are sub-techniques., grouped by TacticThe attacker’s goal at a stage of an attack in MITRE ATT&CK, such as Initial Access or Persistence. Each technique belongs to one or more tactics. in kill-chain order, 2 cited passages 2ExecutionTA0002
Command and Scripting Interpreter T1059 Medium Confidence (technique links)How sure Patchfirst is that an ATT&CK technique applies to this CVE. High and medium links are shown by default; low ones come from early or generic mappings, text matching, or contradict the CVE’s details.
AI mapping from the description · primary impact
XML input yields remote code execution
A remote code execution vulnerability exists in .NET Framework
Malicious File T1204.002 Medium Confidence (technique links)How sure Patchfirst is that an ATT&CK technique applies to this CVE. High and medium links are shown by default; low ones come from early or generic mappings, text matching, or contradict the CVE’s details.
AI mapping from the description · how it is exploited
user opens malicious XML file, UI:R
when the software fails to check the source markup of XML file input
Detection
0 rules for this CVE · 134 general rules for its techniquesRules for this CVE
0Sigma ruleAn open, vendor-neutral detection rule for log data. Security teams convert Sigma rules into searches for their own SIEM. that reference CVE-2020-1147 directly.CVE-specific rules are not available in this build. Search SigmaHQ ↗
General rules for this CVE’s techniques
These detect the technique in general, not this specific vulnerability.
Malicious FileT1204.00239 general rules
- Droppers Exploiting CVE-2017-11882criticalstable
- Ursnif Malware C2 URL Patterncriticalstable
- Exploit for CVE-2017-8759criticaltest
- Potential Maze Ransomware Activitycriticaltest
- File With Uncommon Extension Created By An Office Applicationhightest
- Flash Player Update from Suspicious Locationhightest
- GAC DLL Loaded Via Office Applicationshightest
- HackTool - LittleCorporal Generated Maldoc Injectionhightest
Command and Scripting InterpreterT105995 general rules
- HackTool - Sliver C2 Implant Activity Patterncriticaltest
- Lazarus Group Activitycriticaltest
- REvil Kaseya Incident Malware Patternscriticaltest
- Turla Group Lateral Movementcriticaltest
- Windows Defender AMSI Trigger Detectedhighstable
- Windows Defender Threat Detectedhighstable
- Abusable DLL Potential Sideloading From Suspicious Locationhightest
- Add Insecure Download Source To Wingethightest
Sigma rules © SigmaHQ, Detection Rule License 1.1; linked, not reproduced.
Am I affected? What do I upgrade to?
From GitHub Security Advisories and OSV12 packages in 1 ecosystem. No single main package: each of these ships the affected code.
- NuGetMicrosoft.NETCore.AppAffected: 2.1.0 up to 2.1.20Upgrade to 2.1.20 or later
- NuGetMicrosoft.NETCore.App.Runtime.linux-armAffected: 3.1.0 up to 3.1.6Upgrade to 3.1.6 or later
- NuGetMicrosoft.NETCore.App.Runtime.linux-arm64Affected: 3.1.0 up to 3.1.6Upgrade to 3.1.6 or later
- NuGetMicrosoft.NETCore.App.Runtime.linux-musl-arm64Affected: 3.1.0 up to 3.1.6Upgrade to 3.1.6 or later
- NuGetMicrosoft.NETCore.App.Runtime.linux-musl-x64Affected: 3.1.0 up to 3.1.6Upgrade to 3.1.6 or later
- NuGetMicrosoft.NETCore.App.Runtime.linux-x64Affected: 3.1.0 up to 3.1.6Upgrade to 3.1.6 or later
- NuGetMicrosoft.NETCore.App.Runtime.osx-x64Affected: 3.1.0 up to 3.1.6Upgrade to 3.1.6 or later
- NuGetMicrosoft.NETCore.App.Runtime.rhel.6-x64Affected: 3.1.0 up to 3.1.6Upgrade to 3.1.6 or later
- NuGetMicrosoft.NETCore.App.Runtime.win-armAffected: 3.1.0 up to 3.1.6Upgrade to 3.1.6 or later
- NuGetMicrosoft.NETCore.App.Runtime.win-arm64Affected: 3.1.0 up to 3.1.6Upgrade to 3.1.6 or later
- NuGetMicrosoft.NETCore.App.Runtime.win-x64Affected: 3.1.0 up to 3.1.6Upgrade to 3.1.6 or later
- NuGetMicrosoft.NETCore.App.Runtime.win-x86Affected: 3.1.0 up to 3.1.6Upgrade to 3.1.6 or later
What security researchers reported
Not named in any threat report yetAlso mentioned in 50 community threat pulses (AlienVault OTX)
Weaker evidencePulses are indicator collections that anyone can publish. A mention is not confirmation of exploitation.
- Actively_Exploited_Kev | Oct 29, 202628 Oct 2026
- Actively_Exploited_Kev | Oct 28, 202627 Oct 2026
- Actively_Exploited_Kev | Oct 27, 202626 Oct 2026
- Actively_Exploited_Kev | Oct 24, 202623 Oct 2026
- Actively_Exploited_Kev | Oct 23, 202622 Oct 2026
- Actively_Exploited_Kev | Oct 22, 202621 Oct 2026
- 44 more on OTX