On Mon 2017-06-12 18:56:53, Salvatore Mesoraca wrote: > Introduction of S.A.R.A. USB Filtering. > It uses the "usb_device_auth" LSM hook to provide a mechanism to decide > which USB devices should be authorized to connect to the system and > which shouldn't. > The main goal is to narrow the attack surface for custom USB devices > designed to exploit vulnerabilities found in some USB device drivers. > Via configuration it's possible to allow or to deny authorization, based > on one or more of: Vendor ID, Product ID, bus name and port number. There > is also support for "trailing wildcards".
Hmm. Given that USB device provides vendor id/product id, this does
not really stop anyone, right?
AFAICT you can still get USB stick with vid/pid of logitech keyboard,
and kernel will recognize it as a usb stick.
So you should not really filter on vid/pid, but on device
types (sha sum of USB descriptor?).
> Depending on the configuration, it can work both as a white list or as a
> black list.
Blacklisting vid/pid is completely useless. Whitelisting vid/pid is
nearly so. Attacker able to plug USB devices sees devices already
attached, so he can guess right vid/pids quite easily.
Pavel
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