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.
