A .NET security update has been released for Ubuntu Linux 22.04 LTS and 23.04.

[USN-6427-1] .NET vulnerability

==========================================================================
Ubuntu Security Notice USN-6427-1
October 10, 2023

dotnet6, dotnet7 vulnerability
==========================================================================

A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 23.04
- Ubuntu 22.04 LTS

Summary:

.NET could be made to crash if it received specially crafted network
traffic.

Software Description:
- dotnet6: dotNET CLI tools and runtime
- dotnet7: dotNET CLI tools and runtime

Details:

It was discovered that the .NET Kestrel web server did not properly handle
HTTP/2 requests. A remote attacker could possibly use this issue to cause a
denial of service.

Update instructions:

The problem can be corrected by updating your system to the following
package versions:

Ubuntu 23.04:
  aspnetcore-runtime-6.0           6.0.123-0ubuntu1~23.04.1
  aspnetcore-runtime-7.0           7.0.112-0ubuntu1~23.04.1
  dotnet-host 6.0.123-0ubuntu1~23.04.1
  dotnet-host-7.0                        7.0.112-0ubuntu1~23.04.1
  dotnet-hostfxr-6.0                    6.0.123-0ubuntu1~23.04.1
  dotnet-hostfxr-7.0                    7.0.112-0ubuntu1~23.04.1
  dotnet-runtime-6.0                   6.0.123-0ubuntu1~23.04.1
  dotnet-runtime-7.0                   7.0.112-0ubuntu1~23.04.1
  dotnet-sdk-6.0                         6.0.123-0ubuntu1~23.04.1
  dotnet-sdk-7.0                         7.0.112-0ubuntu1~23.04.1
  dotnet6 6.0.123-0ubuntu1~23.04.1
  dotnet7 7.0.112-0ubuntu1~23.04.1

Ubuntu 22.04 LTS:
  aspnetcore-runtime-6.0           6.0.123-0ubuntu1~22.04.1
  aspnetcore-runtime-7.0           7.0.112-0ubuntu1~22.04.1
  dotnet-host 6.0.123-0ubuntu1~22.04.1
  dotnet-host-7.0                        7.0.112-0ubuntu1~22.04.1
  dotnet-hostfxr-6.0                    6.0.123-0ubuntu1~22.04.1
  dotnet-hostfxr-7.0                    7.0.112-0ubuntu1~22.04.1
  dotnet-runtime-6.0                   6.0.123-0ubuntu1~22.04.1
  dotnet-runtime-7.0                   7.0.112-0ubuntu1~22.04.1
  dotnet-sdk-6.0                         6.0.123-0ubuntu1~22.04.1
  dotnet-sdk-7.0                         7.0.112-0ubuntu1~22.04.1
  dotnet6 6.0.123-0ubuntu1~22.04.1
  dotnet7 7.0.112-0ubuntu1~22.04.1

In general, a standard system update will make all the necessary changes.

References:
  https://ubuntu.com/security/notices/USN-6427-1
  CVE-2023-44487

Package Information:
https://launchpad.net/ubuntu/+source/dotnet6/6.0.123-0ubuntu1~23.04.1
https://launchpad.net/ubuntu/+source/dotnet7/7.0.112-0ubuntu1~23.04.1
https://launchpad.net/ubuntu/+source/dotnet6/6.0.123-0ubuntu1~22.04.1
https://launchpad.net/ubuntu/+source/dotnet7/7.0.112-0ubuntu1~22.04.1