Improper link resolution before file access ('link following') in .NET allows an authorized attacker to elevate privileges locally.

Affected: NuGet: Microsoft.NETCore.App.Runtime.linux-arm, NuGet: Microsoft.NETCore.App.Runtime.linux-arm64, NuGet: Microsoft.NETCore.App.Runtime.linux-musl-arm, NuGet: Microsoft.NETCore.App.Runtime.linux-musl-arm64, NuGet: Microsoft.NETCore.App.Runtime.linux-musl-x64, NuGet: Microsoft.NETCore.App.Runtime.linux-x64, NuGet: Microsoft.NETCore.App.Runtime.osx-arm64, NuGet: Microsoft.NETCore.App.Runtime.osx-x64

## Executive summary

Microsoft is releasing this security advisory to provide information about a vulnerability in Microsoft.NETCore.App.Runtime; System.Private.CoreLib. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability.

Unix named-mutex and shared-memory paths can be manipulated through insecure global directories, symlink races, and unsafe permission changes, allowing local attackers to truncate or overwrite files, widen directory permissions, or elevate privileges.

## Announcement

Announcement for this issue can be found at https://github.com/dotnet/announcements/issues/476

## CVSS Details

- **Version:** 3.1 - **Severity:** High - **Score:** 7.8 - **Vector:** `CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H` - **Weakness:** CWE-59 (Improper Link Resolution Before File Access ('Link Following'))

## Affected Platforms

- **Platforms:** Linux, macOS - **Architectures:** All

## <a name="affected-packages"></a>Affected Packages

The vulnerability affects Microsoft .NET projects that use an affected package version listed below.

Package name | Affected version | Patched version ------------ | ---------------- | --------------- [Microsoft.NETCore.App.Runtime.linux-arm](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-arm) | >= 8.0.0, <= 8.0.31 | 8.0.32 [Microsoft.NETCore.App.Runtime.linux-arm64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.linux-arm64) | >= 8.0.0, <= 8.…