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.NET Core Elevation of Privilege Vulnerability

High severity GitHub Reviewed Published Aug 10, 2021 in dotnet/runtime • Updated Jan 30, 2023

Package

nuget Microsoft.NETCore.App.Runtime.Mono.LLVM.AOT.linux-arm64 (NuGet)

Affected versions

>= 5.0.0, < 5.0.9

Patched versions

5.0.9
nuget Microsoft.NETCore.App.Runtime.Mono.LLVM.AOT.linux-x64 (NuGet)
>= 5.0.0, < 5.0.9
5.0.9
nuget Microsoft.NETCore.App.Runtime.Mono.LLVM.AOT.osx-x64 (NuGet)
>= 5.0.0, < 5.0.9
5.0.9
nuget Microsoft.NETCore.App.Runtime.Mono.LLVM.linux-arm64 (NuGet)
>= 5.0.0, < 5.0.9
5.0.9
nuget Microsoft.NETCore.App.Runtime.Mono.LLVM.linux-x64 (NuGet)
>= 5.0.0, < 5.0.9
5.0.9
nuget Microsoft.NETCore.App.Runtime.Mono.LLVM.osx-x64 (NuGet)
>= 5.0.0, < 5.0.9
5.0.9
nuget Microsoft.NETCore.App.Runtime.Mono.linux-arm (NuGet)
>= 5.0.0, < 5.0.9
5.0.9
nuget Microsoft.NETCore.App.Runtime.Mono.linux-arm64 (NuGet)
>= 5.0.0, < 5.0.9
5.0.9
nuget Microsoft.NETCore.App.Runtime.Mono.linux-musl-x64 (NuGet)
>= 5.0.0, < 5.0.9
5.0.9
nuget Microsoft.NETCore.App.Runtime.Mono.linux-x64 (NuGet)
>= 5.0.0, < 5.0.9
5.0.9
nuget Microsoft.NETCore.App.Runtime.Mono.osx-x64 (NuGet)
>= 5.0.0, < 5.0.9
5.0.9
nuget Microsoft.NETCore.App.Runtime.linux-arm (NuGet)
>= 3.1.0, < 3.1.18
>= 5.0.0, < 5.0.9
3.1.18
5.0.9
nuget Microsoft.NETCore.App.Runtime.linux-arm64 (NuGet)
>= 3.1.0, < 3.1.18
>= 5.0.0, < 5.0.9
3.1.18
5.0.9
nuget Microsoft.NETCore.App.Runtime.linux-musl-arm (NuGet)
>= 5.0.0, < 5.0.9
5.0.9
nuget Microsoft.NETCore.App.Runtime.linux-musl-arm64 (NuGet)
>= 3.1.0, < 3.1.18
>= 5.0.0, < 5.0.9
3.1.18
5.0.9
nuget Microsoft.NETCore.App.Runtime.linux-musl-x64 (NuGet)
>= 3.1.0, < 3.1.18
>= 5.0.0, < 5.0.9
3.1.18
5.0.9
nuget Microsoft.NETCore.App.Runtime.linux-x64 (NuGet)
>= 3.1.0, < 3.1.18
>= 5.0.0, < 5.0.9
3.1.18
5.0.9
nuget Microsoft.NETCore.App.Runtime.osx-x64 (NuGet)
>= 3.1.0, < 3.1.18
>= 5.0.0, < 5.0.9
3.1.18
5.0.9
nuget Microsoft.NETCore.App.Runtime.rhel.6-x64 (NuGet)
>= 3.1.0, < 3.1.18
3.1.18
nuget Microsoft.NETCore.App.Runtime.win-arm (NuGet)
>= 3.1.0, < 3.1.18
>= 5.0.0, < 5.0.9
3.1.18
5.0.9
nuget Microsoft.NETCore.App.Runtime.win-arm64 (NuGet)
>= 3.1.0, < 3.1.18
>= 5.0.0, < 5.0.9
3.1.18
5.0.9
nuget Microsoft.NETCore.App.Runtime.win-x64 (NuGet)
>= 3.1.0, < 3.1.18
>= 5.0.0, < 5.0.9
3.1.18
5.0.9
nuget Microsoft.NETCore.App.Runtime.win-x86 (NuGet)
>= 3.1.0, < 3.1.18
>= 5.0.0, < 5.0.9
3.1.18
5.0.9

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 in .NET 5.0, .NET Core 3.1 and .NET Core 2.1 where .NET (Core) server applications providing WebSocket endpoints could be tricked into endlessly looping while trying to read a single WebSocket frame.

Patches

Other Details

References

@rbhanda rbhanda published to dotnet/runtime Aug 10, 2021
Published by the National Vulnerability Database Aug 12, 2021
Published to the GitHub Advisory Database Oct 25, 2022
Reviewed Oct 25, 2022
Last updated Jan 30, 2023

Severity

High

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS score

0.193%
(58th percentile)

Weaknesses

No CWEs

CVE ID

CVE-2021-26423

GHSA ID

GHSA-rh58-r7jh-xhx3

Source code

No known source code
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