As far as I can tell from Microsoft's documentation, WinAPI access for ACLs was added in Windows 10, which Rust 1.0 predates. And std::fs attempts to provide both minimalist and cross-platform APIs, which in practice means (for better or worse) it's the lowest common denominator between Windows and Unix, with the objective being that higher-level libraries can leverage it as a building block. From the documentation for std::fs:

"This module contains basic methods to manipulate the contents of the local filesystem. All methods in this module represent cross-platform filesystem operations. Extra platform-specific functionality can be found in the extension traits of std::os::$platform."

Following its recommendation, if we look at std::os::windows::fs we see an extension trait for setting Windows-specific flags for WinAPI-specific flags, like dwDesiredAccess, dwShareMode, dwFlagsAndAttributes. I'm not a Windows dev but AFAICT we want an API to set lpSecurityAttributes. I don't see an option for that in std::os::windows::fs, likely complicated by the fact that it's a pointer, so acquiring a valid value for that parameter is more involved than just constructing a bitfield like for the aforementioned parameters. But if you think this should be simple, then please propose adding it to std::os::windows::fs; the Rust stdlib adds new APIs all the time in response to demand. (In the meantime, comprehensive Windows support is generally provided by the de-facto standard winapi crate, which provides access to the raw syscall).