Out-of-bounds write in .NET allows an unauthorized attacker to execute code over a network.

Affected: NuGet: Microsoft.NETCore.App.Runtime.win-arm64, NuGet: Microsoft.NETCore.App.Runtime.win-x64, NuGet: Microsoft.NETCore.App.Runtime.win-x86

## Executive summary

Microsoft is releasing this security advisory to provide information about a vulnerability in System.Net.Sockets. This advisory also provides guidance on what developers can do to update their applications to remove this vulnerability.

On Windows, reusing a `SocketAsyncEventArgs` instance across IPv4 and IPv6 datagram sockets can retain an undersized cached native address buffer, allowing an unauthenticated out-of-bounds write during `ReceiveFromAsync`.

## Announcement

Announcement for this issue can be found at https://github.com/dotnet/announcements/issues/466

## CVSS Details

- **Version:** 3.1 - **Severity:** High - **Score:** 8.1 - **Vector:** `CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H`

- **Weakness:** CWE-787 (Out-of-bounds Write) ## Affected Platforms

- **Platforms:** Windows - **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.win-arm](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.win-arm) | >= 8.0.0, <= 8.0.31 | 8.0.32 [Microsoft.NETCore.App.Runtime.win-arm64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.win-arm64) | >= 8.0.0, <= 8.0.31 | 8.0.32 [Microsoft.NETCore.App.Runtime.win-x64](https://www.nuget.org/packages/Microsoft.NETCore.App.Runtime.win-x…