Cyber Resilience

CVE-2020-0646

Microsoft .Net Framework 3.0 … 4.8

CISA KEVActive ExploitationEUVD ExploitedPublic PoC
Published
14 January 2020
Modified
29 October 2025
KEV Added
03 November 2021
Patch / advisory
CVSS Score v3.1 9.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.99 99.9th percentile
Risk Priority 97 floored blend · peak EPSS

Summary

CVE-2020-0646 is a critical-severity aka Blind XPath Injection (CWE-91) vulnerability in Microsoft .Net Framework. Its CVSS base score is 9.8 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Content Injection (T1659); ranked in the top 0.1% of CVEs by exploit likelihood; CISA has added it to the Known Exploited Vulnerabilities catalog; a public proof-of-concept is referenced.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

A remote code execution vulnerability exists in the Microsoft .NET Framework when it fails to properly validate input, tracked as CVE-2020-0646 with a CVSS score of 9.8. The flaw is also referenced in connection with SharePoint workflows via XOML injection and is assigned CWE-91 for XML injection issues.

The vulnerability can be exploited remotely by an unauthenticated attacker over the network without user interaction, enabling full compromise of confidentiality, integrity, and availability on affected systems.

Microsoft security advisories at portal.msrc.microsoft.com address the issue and provide patch guidance, while CISA lists the CVE in its known exploited vulnerabilities catalog.

Public exploit references, including PacketStorm disclosures on SharePoint workflow injection, confirm active interest and real-world exploitation potential.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

A remote code execution vulnerability exists when the Microsoft .NET Framework fails to validate input properly, aka '.NET Framework Remote Code Execution Injection Vulnerability'.

CWE(s)
KEV Date Added
03 November 2021

Related Threats

MITRE ATT&CK Enterprise Techniques

T1659 Content Injection Initial Access
Adversaries may gain access and continuously communicate with victims by injecting malicious content into systems through online network traffic.
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2020-0674Same product: Microsoft Windows 10 1507both on KEV
CVE-2020-0968Same product: Microsoft Windows 10 1507both on KEV
CVE-2020-1020Same product: Microsoft Windows 10 1507both on KEV
CVE-2020-1380Same product: Microsoft Windows 10 1507both on KEV
CVE-2019-1429Same product: Microsoft Windows 10 1507both on KEV
CVE-2020-17087Same product: Microsoft Windows 10 1507both on KEV
CVE-2020-1027Same product: Microsoft Windows 10 1507both on KEV
CVE-2020-0938Same product: Microsoft Windows 10 1507both on KEV
CVE-2020-1054Same product: Microsoft Windows 10 1507both on KEV
CVE-2018-8639Same product: Microsoft Windows 10 1507both on KEV

Affected Assets

microsoft
.net framework
3.0, 3.5, 3.5.1, 4.5.2, 4.6

Mitigating Controls

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC directly requires input neutralization and validation that eliminates XML injection flaws.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

finds

Security testing catches XML injection during development but does not itself implement the fix.

A.8.15 Logging partial match
finds

Logging can record injection attempts for detection but does not prevent the weakness.

finds

Monitoring can detect exploitation but provides no preventive control over XML handling.

prevents

Secure SDLC mandates input validation and output encoding that directly prevent XML injection.

prevents

Application security requirements explicitly call for defenses against injection flaws including XML.

prevents

Secure architecture principles reduce attack surface but do not prescribe XML-specific controls.

References