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

On Wed, 2022-11-23 at 16:40 +0100, Nicolas Cavallari wrote:

On 23/11/2022 13:46, Greg Kroah-Hartman wrote:

quoted

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 ?

Yes, there are.

Another class of WWAN dongles presented as USB RNDIS to the host, had
an onboard DHCP server, and "bridged" that (for lack of a better term)
to the WWAN. And like a home router exposed HTTP based management on
192.168.1.1 to control the WWAN stuff.

https://openwrt.org/docs/guide-user/network/wan/wwan/ethernetoverusb_rndis

RE Wifi, (echoing Johannes) there was one Broadcom chipset, but a bunch
of devices used it. I have some though I don't actively use them. But
they still work...

Dan

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