full-disclosure - state of homograph attacks

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From: prb at lava.net (Peter Besenbruch)
Subject: state of homograph attacks

Markus Wernig wrote:
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
> 
> Valdis.Kletnieks@...edu wrote:
> | On Mon, 07 Feb 2005 11:06:18 PST, Richard Jacobsen said:
> |
> |
> |>Open up firefox, put about:config into the address bar, and then change
> |>network.enableIDN to false by double clicking on it.  If it is working
> |>successfully, you should get a message "domainname.com could not be
> found"
> |>when clicking on an IDN link.  You shouldn't need to restart your 
> browser.
> |
> |
> | The actual bug referenced by Gerald is that if you use about:config to
> set it,
> | it *works* without having to restart, but at the next restart of the
> browser,
> | the setting no longer works...
> |
> 
> Yes, it does set network.enableIDN = false, but on startup this seems to
> get ignored. What I had to do to disable it (probably a brute hack):
> there's a line in ~/.mozilla/firefox/whatever.default/compreg.dat that
> reads along the lines of
> "{4byteshex-2byteshex-2byteshex-2byteshex-6byteshex},@mozilla.org/network/idn-service;1,,nsIDNService,rel:libnecko.so" 
> 
> 
> The head of the file says "don't edit", but after deleting the above
> line, firefox wasn't able to resolve the punycode url anymore after a
> restart.

Unfortunately, Firefox 1.0 for Linux still displays punycode after 
deleting the line. They demo on http://www.shmoo.com/idn/ still works.

I should also point out that Konqueror 3.3.2 is also vulnerable, but the 
the SSL demo brings up a certification warning. To the clueless, such a 
warning might not do much, but to some, a bad certification on an SSL 
page is a red flag.

Perhaps we should all ask Microsoft to port Internet Explorer to Linux. 
That way we would all be safe.

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