CVE-2023-22466

### Impact When configuring a Windows named pipe server, setting `pipe_mode` will reset `reject_remote_clients` to `false`. If the application has previously configured `reject_remote_clients` to `true`, this effectively undoes the configuration. This also applies if `reject_remote_clients` is not explicitly set as this is the default configuration and is cleared by calling `pipe_mode`. Remote clients may only access the named pipe if the named pipe's associated path is accessible via a publically shared folder (SMB). ### Patches The following versions have been patched: * 1.23.1 * 1.20.3 * 1.18.4 The fix will also be present in all releases starting from version 1.24.0. Named pipes were introduced to Tokio in version 1.7.0, so releases older than 1.7.0 are not affected. ### Workarounds Ensure that `pipe_mode` is set **first** after initializing a `ServerOptions`. For example: ```rust let mut opts = ServerOptions::new(); opts.pipe_mode(PipeMode::Message); opts.reject_remote_clients(true); ``` ### References https://learn.microsoft.com/en-us/windows/win32/api/winbase/nf-winbase-createnamedpipea#pipe_reject_remote_clients

On Windows, configuring a named pipe server with [pipe_mode] will force [ServerOptions]::[reject_remote_clients] as `false`. This drops any intended explicit configuration for the [reject_remote_clients] that may have been set as `true` previously. The default setting of [reject_remote_clients] is normally `true` meaning the default is also overridden as `false`. ## Workarounds Ensure that [pipe_mode] is set first after initializing a [ServerOptions]. For example: ```rust let mut opts = ServerOptions::new(); opts.pipe_mode(PipeMode::Message); opts.reject_remote_clients(true); ``` [ServerOptions]: https://docs.rs/tokio/latest/tokio/net/windows/named_pipe/struct.ServerOptions.html [pipe_mode]: https://docs.rs/tokio/latest/tokio/net/windows/named_pipe/struct.ServerOptions.html#method.pipe_mode [reject_remote_clients]: https://docs.rs/tokio/latest/tokio/net/windows/named_pipe/struct.ServerOptions.html#method.reject_remote_clients