Re: [PATCH] USB: disable all RNDIS protocol drivers

Nicolas Cavallari
2022-11-23T15:41:54Z

On 23/11/2022 13:46, Greg Kroah-Hartman wrote:
> The Microsoft RNDIS protocol is, as designed, insecure and vulnerable on
> any system that uses it with untrusted hosts or devices. Because the
> protocol is impossible to make secure, just disable all rndis drivers to
> prevent anyone from using them again.
>
> Windows only needed this for XP and newer systems, Windows systems older
> than that can use the normal USB class protocols instead, which do not
> have these problems.
>
> Android has had this disabled for many years so there should not be any
> real systems that still need this.

I kind of disagree here. I have seen plenty of android devices that only
support rndis for connection sharing, including my android 11 phone
released in Q3 2020. I suspect the qualcomm's BSP still enable it by
default.

There are also probably cellular dongles that uses rndis by default.
Maybe ask the ModemManager people ?

I'm also curious if reimplementing it in userspace would solve the
security problem.