<aside from main conversation> Would it be a good community gesture to join Microsoft in trying to eradicate IE6?
http://TheIE6Countdown.com or to not join them and put up a more general banner http://IE6NoMore.com and move on? </aside from main conversation> On 03Jun2011, at 10:53 AM, Brion Vibber wrote: > On Thu, Jun 2, 2011 at 5:21 PM, Tim Starling <[email protected]>wrote: > >> On 03/06/11 06:56, Brion Vibber wrote: >>> For 1) I'm honestly a bit willing to sacrifice a few IE 6 users at this >>> point; the vendor's dropped support, shipped three major versions, and is >>> actively campaigning to get the remaining users to upgrade. :) But I get >>> protecting, so if we can find a workaround that's ok. >> >> We can't really do this without sending "Vary: User-Agent", which >> would completely destroy our cache hit ratio. For people who use Squid >> with our X-Vary-Options patch, it would be possible to use a very long >> X-Vary-Options header to single out IE 6 requests, but not everyone >> has that patch. >> > > I'm really thinking more along the lines of: if someone's an IE 6-or-below > user they have hundreds of other exploit vectors staring them in the face > too, and we can't protect them against many of them -- or ANY of them if > they're visiting other sites than just an up-to-date MediaWiki. > > The cost of this fix has been immense; several versions of the fix with > varying levels of disruption on production sites, both for IE 6 users and > non-IE 6 users, and several weeks of delay on the 1.17.0 release. > > I'd be willing to accept a few drive-by downloads for IE 6 users; it's not > ideal but it's something that their antivirus tools etc will already be > watching out for, that end-users already get trained to beware of, and that > will probably *still* be exploitable on other web sites that they visit > anyway. > > > The main issue here is that we don't a wide variety of web servers set >> up for testing. We know that Apache lets you detect %2E versus dot via >> $_SERVER['REQUEST_URI'], but we don't know if any other web servers do >> that. >> >> Note that checking for %2E alone is not sufficient, a lot of >> installations (including Wikimedia) have an alias /wiki -> >> /w/index.php which can be used to exploit action=raw. >> > > Well that should be fine; as long as we can see the "/wiki?/foo.bat" then we > can identify that it doesn't contain an unencoded dot in the path. > > It sounds like simply checking REQUEST_URI when available would eliminate a > huge portion of our false positives that affect real-world situations. > Apache is still the default web server in most situations for most folks, > and of course runs our own production servers. > > >> >>> Are there any additional exploit vectors for API output other than HTML >> tags >>> mixed unescaped into JSON? >> >> Yes, all other content types, as I said above. >> > > Only as drive-by downloads, or as things that execute without interaction? > > >> I think the current solution in trunk, plus the redirect idea that >> I've been discussing with Roan, is our best bet for now, unless >> someone wants to investigate $_SERVER['REQUEST_URI']. >> > > *nod* Checking REQUEST_URI is probably the first thing we should do when > it's available. > > >> If there is an actual problem with ForeignAPIRepo then we can look at >> server-side special cases for it. But r89248 should allow all API >> requests that have a dotless value in their last GET parameter, and a >> quick review of ForeignAPIRepo in 1.16 and trunk indicates that it >> always sends such requests. >> > > Yay! That's one less thing to worry about. :D > > >> Since we're talking about discarded solutions for this, maybe it's >> worth noting that I also investigated using a Content-Disposition >> header. The vulnerability involves an incorrect cache filename, and >> it's possible to override the cache filename using a >> Content-Disposition "filename" parameter. The reason I gave up on it >> is because we already use Content-Disposition for wfStreamFile(): >> >> header( "Content-Disposition: >> inline;filename*=utf-8'$wgLanguageCode'" . urlencode( basename( $fname >> ) ) ); >> >> IE 6 doesn't understand the charset specification, so it ignores the >> header and goes back to detecting the extension. >> > > Good to know. > > -- brion > _______________________________________________ > Wikitech-l mailing list > [email protected] > https://lists.wikimedia.org/mailman/listinfo/wikitech-l _______________________________________________ Wikitech-l mailing list [email protected] https://lists.wikimedia.org/mailman/listinfo/wikitech-l
