Re: [CFR]RT305xF support, w/o attachment

> Date: Tue, 22 Mar 2011 06:46:12 -0400
> From: Etienne Robillard <erob_at_gthcfoundation.org>
> Subject: Re: [CFR]RT305xF support, w/o attachment
> To: Adrian Chadd <adrian_at_freebsd.org>
> Cc: freebsd-current_at_freebsd.org
> Message-ID: <4D887DF4.6060602_at_gthcfoundation.org>
> Content-Type: text/plain; charset=ISO-8859-1
> 
> as far my knowledge goes, radiation from multi-frequency
> subcarriers in
> a multi-path
> system such as a wireless network (802.11 a/g/n) or a
> "microwave oven"
> is something
> you definitely want to avoid sitting in while hacking
> FreeBSD...
> 
> https://gthc.org/wiki/Advisories/OFDM_20110315
> 
> I may have done technical errors but i do not drink in the
> morning!! :)
> 
> 
> 
> 
> On 22/03/11 06:30 AM, Adrian Chadd wrote:
> > So I'm curious - what exactly about OFDM do you have a
> problem with?
> >
> >
> >
> >
> > Adrian

I have looked at your "security advisory" and also fail to understand what you are complaining about: "Problem Description

The OFDM (Orthogonal Frequency Division Multiplexing) modulation scheme as implemented in the upper 802.11 protocol for Wireless LAN (WLAN) networking is inherently insecure as designed to allow multi-frequency radiation of arbitrary Q-I numbers access in the unregulated ISM band/range."

A high-Q signal has a very sharp peak and narrow pass-band. This lets the radio get past the noise floor using less transmitter energy.


I am not sure what a Q-I number is. You use the word "arbitrary." Are you claiming that OFDM allows the radios to exceed emission limits? As the other person commented, radio emmisions are regulated, even in the unlicensed spectrum.

It would only be a security/safety issue if the radio exceeds legal limits. Your bounty suggests you have little/no evidence these limits are actually exceeded.

A priviledge escalation exploit reprogramming a software-implemented radio to exceed radiation limits would be a concern, but it won't "cook" nearby users. The hardware would overheat before that happens.

I agree excessive RF exposure should be avoided. I keep my wireless Access Point at its minimum power setting (1/4 power, 802.11g).

Regards,

James Phillips