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Fencer Vulns
high 8.8

CVE-2021-43877 json

ASP.NET Core and Visual Studio Elevation of Privilege Vulnerability

published 2021-12-15 4 y ago modified 2026-11-02 6 d ago also BIT-aspnet-core-2021-43877 , EUVD-2021-30739

cvss
8.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.7%
EPSS 0.7% chance of exploitation in 30 days, percentile 54%
public exploits
0
none known

Summary

ASP.NET Core and Visual Studio Elevation of Privilege Vulnerability

Patch / fix

  • bitnami aspnet-core 3.1.1, 5.0.1, 6.0.1
  • Microsoft Microsoft Visual Studio 2019 version 16.7 (includes 16.0 – 16.6) 16.7.23
  • Microsoft Microsoft Visual Studio 2019 version 16.9 (includes 16.0 - 16.8) 16.9.15
  • Microsoft Microsoft Visual Studio 2019 version 16.11 (includes 16.0 - 16.10) 16.11.8
  • Microsoft Microsoft Visual Studio 2022 version 17.0 17.0.3
  • Microsoft ASP.NET Core 3.1 3.1.22
  • Microsoft ASP.NET Core 5.0 5.0.13
  • Microsoft ASP.NET Core 6.0 6.0.101
  • Microsoft Microsoft Visual Studio 2022 version 17.1 17.1.4

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2021-43877 updated cvss 7.8

dotnet: ASPNetCore processPath privilege escalation

  • Red Hat .NET Core 3.1 on Red Hat Enterprise Linux rh-dotnet31, rh-dotnet31-runtime Red Hat .NET Core 5.0 on Red Hat Enterprise Linux rh-dotnet50, rh-dotnet50-runtime Red Hat Enterprise Linux 8 dotnet, dotnet3.1, dotnet5.0, dotnet6.0, dotnet-host, dotnet-sdk-3.1, +27 more Red Hat Enterprise Linux 9 dotnet3.1
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
31 d ago

Exploit prediction

0.73% chance of exploitation in the next 30 days, higher than 54% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 8.8 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
CNA 3.1 8.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
CNA 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 4.6 AV:L/AC:L/Au:N/C:P/I:P/A:P
OSV 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected packages

ecosystem package affected fixed in
bitnami aspnet-core
>=3.1.0, <3.1.1
>=5.0.0, <5.0.1
>=6.0.0, <6.0.1
3.1.1
5.0.1
6.0.1

Affected products

  • 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)
  • Microsoft Microsoft Visual Studio 2022 version 17.0
  • Microsoft ASP.NET Core 3.1
  • Microsoft ASP.NET Core 5.0
  • Microsoft ASP.NET Core 6.0
  • Microsoft Microsoft Visual Studio 2022 version 17.1

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.