CoreWCF NetFraming based services can leave connections open when they should be closed

Vulnerability Description

CoreWCF is a port of the service side of Windows Communication Foundation (WCF) to .NET Core. If you have a NetFraming based CoreWCF service, extra system resources could be consumed by connections being left established instead of closing or aborting them. There are two scenarios when this can happen. When a client established a connection to the service and sends no data, the service will wait indefinitely for the client to initiate the NetFraming session handshake. Additionally, once a client has established a session, if the client doesn't send any requests for the period of time configured in the binding ReceiveTimeout, the connection is not properly closed as part of the session being aborted. The bindings affected by this behavior are NetTcpBinding, NetNamedPipeBinding, and UnixDomainSocketBinding. Only NetTcpBinding has the ability to accept non local connections. The currently supported versions of CoreWCF are v1.4.x and v1.5.x. The fix can be found in v1.4.2 and v1.5.2 of the CoreWCF packages. Users are advised to upgrade. There are no workarounds for this issue.

References

• https://github.com/CoreWCF/CoreWCF/security/advisories/GHSA-32jq-mv89-5rx7
• https://github.com/CoreWCF/CoreWCF/issues/1345