Vulnerabilities in pkg:nuget/Microsoft.NETCore.App.Ref

PACKAGE
Advisory Identifier: GHSA-mcwm-2wmc-6hv4
Advisory Summary

CVE-2021-31957 is a HIGH (CVSS 7.5) denial of service vulnerability (General Security Weakness) affecting Microsoft.NETCore.App.Ref libraries in the NuGet ecosystem. The issue involves asp.net core denial of service vulnerability. Remediation is available by upgrading affected packages to version 3.1.16, 5.0.7.

1 Known Advisory Record(s)
Package Vulnerability Intelligence

pkg:nuget/Microsoft.NETCore.App.Ref

1 Known Advisory Record(s)

Vulnerability advisories affecting package pkg:nuget/Microsoft.NETCore.App.Ref. Select an advisory below to view technical details or fixes.

Advisory ID CVE / NVD Severity Summary
GHSA-mcwm-2wmc-6hv4 CVE-2021-31957 HIGH ASP.NET Core Denial of Service Vulnerability

CVE-2021-31957 at a Glance

CVE Identifier CVE-2021-31957
GHSA Identifier GHSA-mcwm-2wmc-6hv4
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification General Security Weakness
Affected Product Microsoft.NETCore.App.Ref
Package Ecosystem NuGet
Published Date
Last Updated

Security Impact

CVSS: 7.5

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality None (C:N)
Integrity None (I:N)
Availability High (A:H)

How to Fix CVE-2021-31957

To remediate this vulnerability, upgrade all affected Microsoft.NETCore.App.Ref dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

Microsoft.NETCore.App.Ref fixed: 3.1.16
Upgrade Microsoft.NETCore.App.Ref to 3.1.16
Microsoft.NETCore.App.Ref fixed: 5.0.7
Upgrade Microsoft.NETCore.App.Ref to 5.0.7
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release:

inspect dependencies for Microsoft.NETCore.App.Ref

How to Check if You Are Affected

To determine whether your application is affected by CVE-2021-31957, inspect your project dependencies for Microsoft.NETCore.App.Ref:

inspect dependencies for Microsoft.NETCore.App.Ref

Analyze the terminal output to locate any version of Microsoft.NETCore.App.Ref in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 3.1.16), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under General Security Weakness. In Microsoft.NETCore.App.Ref, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

# Withdrawn This advisory was initially published and mapped incorrectly to nuget `Microsoft.NETCore.App.Ref`. We later reanalyzed this advisory and found it does not have a direct mapping to a NuGet package. Thus we have withdrawn this advisory. The underlying ASP.NET Core Denial of Service Vulnerability and CVE-2021-31957 remain legitimate. # Description. Microsoft is releasing this security advisory to provide information about a vulnerability in .NET 5.0 and .NET Core 3.1. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability. A denial of service vulnerability exists when ASP.NET Core improperly handles client disconnect. An attacker who successfully exploited this vulnerability could cause a denial of service against an ASP.NET Core web application. The vulnerability can be exploited remotely, without authentication. ### Patches * If you're using .NET 5.0, you should download and install Runtime 5.0.7 or SDK 5.0.204 (for Visual Studio 2019 v16.8) or SDK 5.0.301 (for Visual Studio 2019 16.10) from https://dotnet.microsoft.com/download/dotnet-core/5.0. * If you're using .NET Core 3.1, you should download and install Runtime 3.1.16 or SDK 3.1.116 (for Visual Studio 2019 v16.4) or 3.1.410 (for Visual Studio 2019 v16.5 or later) from https://dotnet.microsoft.com/download/dotnet-core/3.1. #### Other Details - Announcement for this issue can be found at https://github.com/dotnet/announcements/issues/188 - An Issue for this can be found at https://github.com/dotnet/aspnetcore/issues/33369 - MSRC details for this can be found at https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2021-31957

CVE-2021-31957 Affected Microsoft.NETCore.App.Ref Versions

2 component(s)
Fixed Versions:
3.1.165.0.7
Product / Package Ecosystem Affected Versions Fixed Version
Microsoft.NETCore.App.Ref
NuGet
< 3.1.16
3.1.16
Microsoft.NETCore.App.Ref
NuGet
≥ 5.0.0
< 5.0.7
5.0.7

References

Frequently Asked Questions

What is CVE-2021-31957?
CVE-2021-31957 is a security vulnerability in Microsoft.NETCore.App.Ref involving ASP.NET Core Denial of Service Vulnerability under General Security Weakness.
Which Microsoft.NETCore.App.Ref versions are affected?
Affected versions include releases prior to 3.1.16, 5.0.7 across affected packages: Microsoft.NETCore.App.Ref.
What version fixes CVE-2021-31957?
Upgrading to 3.1.16, 5.0.7 (or the latest patched release for your respective branch) resolves the vulnerability.
Is Microsoft.NETCore.App.Ref affected?
Yes, Microsoft.NETCore.App.Ref is affected in releases prior to 3.1.16, 5.0.7. Upgrade your dependency to 3.1.16, 5.0.7 or later.
What is the CVSS score of CVE-2021-31957?
CVE-2021-31957 has a CVSS v3.1 base score of 7.5 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
What CWE is associated with CVE-2021-31957?
CVE-2021-31957 is classified under General Security Weakness.
How can I check NuGet dependencies for CVE-2021-31957?
Run the dependency tree command: 'inspect dependencies for Microsoft.NETCore.App.Ref'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-mcwm-2wmc-6hv4",
  "modified" : "2021-10-06T00:23:01Z",
  "published" : "2021-10-06T00:23:01Z",
  "withdrawn" : "2021-10-06T00:23:01Z",
  "aliases" : [ "CVE-2021-31957" ],
  "summary" : "ASP.NET Core Denial of Service Vulnerability",
  "details" : "# Withdrawn\n\nThis advisory was initially published and mapped incorrectly to nuget `Microsoft.NETCore.App.Ref`. We later reanalyzed this advisory and found it does not have a direct mapping to a NuGet package.  Thus we have withdrawn this advisory.\n\nThe underlying ASP.NET Core Denial of Service Vulnerability and CVE-2021-31957 remain legitimate.\n\n# Description.\n\nMicrosoft is releasing this security advisory to provide information about a vulnerability in .NET 5.0 and .NET Core 3.1. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability.\n\nA denial of service vulnerability exists when ASP.NET Core improperly handles client disconnect. An attacker who successfully exploited this vulnerability could cause a denial of service against an ASP.NET Core web application. The vulnerability can be exploited remotely, without authentication.\n\n\n### Patches\n\n* If you're using .NET 5.0, you should download and install Runtime 5.0.7 or SDK 5.0.204 (for Visual Studio 2019 v16.8) or SDK 5.0.301 (for Visual Studio 2019 16.10) from https://dotnet.microsoft.com/download/dotnet-core/5.0.\n\n* If you're using .NET Core 3.1, you should download and install Runtime 3.1.16 or SDK 3.1.116 (for Visual Studio 2019 v16.4) or 3.1.410 (for Visual Studio 2019 v16.5 or later) from https://dotnet.microsoft.com/download/dotnet-core/3.1.\n\n\n\n#### Other Details\n\n- Announcement for this issue can be found at https://github.com/dotnet/announcements/issues/188\n- An Issue for this can be found at https://github.com/dotnet/aspnetcore/issues/33369\n- MSRC details for this can be found at https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2021-31957\n",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Microsoft.NETCore.App.Ref"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "3.1.16"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Microsoft.NETCore.App.Ref"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "5.0.0"
      }, {
        "fixed" : "5.0.7"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/dotnet/aspnetcore/security/advisories/GHSA-mcwm-2wmc-6hv4"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-31957"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/dotnet/aspnetcore"
  }, {
    "type" : "WEB",
    "url" : "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/4PRVVLXXQEF4SEJOBV3VRJHGX7YHY2CG"
  }, {
    "type" : "WEB",
    "url" : "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/CVCDYIP4A6DDRT7G6P3ZW6PKNK2DNWJ2"
  }, {
    "type" : "WEB",
    "url" : "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/PMHWHRRYDHKM6BIINW5V7OCSW4SDWB4W"
  }, {
    "type" : "WEB",
    "url" : "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/VMAO4NG2OQ4PCXUQWMNSCMYWLIJJY6UY"
  }, {
    "type" : "WEB",
    "url" : "https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-31957"
  } ],
  "database_specific" : {
    "cwe_ids" : [ ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2021-10-05T19:41:18Z",
    "nvd_published_at" : "2021-06-08T23:15:00Z"
  }
}