Bugtraq mailing list archives
Re: The Dangers of Allowing Users to Post Images
From: Jason Bowman <jasonb42 () mediaone net>
Date: Thu, 2 Aug 2001 21:50:57 -0400
On Tuesday 31 July 2001 12:40 pm, Dan Harkless wrote:
Michal Szokolo <msz () kill-spammers pmp com pl> writes:John Percival wrote:I'm going to try and throw another issue into this discussion now too: denial of service. We have discussed it for attacking remote servers, but not for the client viewing the image. It's something else that I spotted while I was playing around with this issue just now. If you have images that include a mailto:me () my host somewhere com source, then the default handler for mailto: links is opened up. Be that Outlook, Netscape Composer, Eudora, or whatever else you care to use. So if someone embedded 100 (arbitrary figure) mailto: images in a page, then this would do a lot of harm to the user's computer. At best, it would get very busy for a few minutes creating new emails, and would be a pain to clear up. At worst, it could bring the whole system crashing down.Netscape 4.77 crashes at about 50 such IMG tags, IF they are different (simply putting mailto:fakeluser@fakedomain 100 times won't work (opens only 2 message windows)), but if you go with some script... instant crash (try it now free of charge at http://msz.pmp.com.pl/boom/ ;-)).Sorry for the very late reply to this thread, but in case anybody's wondering whether the recently-released 4.78 fixes this bug, it does not. When I visit the page, though (and perhaps on version 4.78 in general), it doesn't crash until you click on the close box for one of the Composer windows. I tested on Win2K Pro.
I tried your crash page in the Konqueror browser, KDE 2.1.1 in linux, RH 7.1 and it did not effect me. You should try htp://robynin.com/ for a really annoying script... Not exactly a DOS but still fun : ) Jason B. PS: Netscape 4 users beware of the page I referenced. While in IE the page is annoying the way Netscape 4 handles the javascript it can be nasty... similar to a DOS.
Current thread:
- The Dangers of Allowing Users to Post Images Matt Block (Aug 01)
- <Possible follow-ups>
- Re: The Dangers of Allowing Users to Post Images Paul de Vrieze (Aug 01)
- Re: The Dangers of Allowing Users to Post Images Jason Bowman (Aug 02)