From owner-freebsd-security Fri Jan 21 20:56: 8 2000 Delivered-To: freebsd-security@freebsd.org Received: from rover.village.org (rover.village.org [204.144.255.49]) by hub.freebsd.org (Postfix) with ESMTP id C976314E35 for ; Fri, 21 Jan 2000 20:55:56 -0800 (PST) (envelope-from imp@harmony.village.org) Received: from harmony.village.org (harmony.village.org [10.0.0.6]) by rover.village.org (8.9.3/8.9.3) with ESMTP id VAA87623; Fri, 21 Jan 2000 21:52:49 -0700 (MST) (envelope-from imp@harmony.village.org) Received: from harmony.village.org (localhost.village.org [127.0.0.1]) by harmony.village.org (8.9.3/8.8.3) with ESMTP id VAA17629; Fri, 21 Jan 2000 21:52:58 -0700 (MST) Message-Id: <200001220452.VAA17629@harmony.village.org> To: Brett Glass Subject: Re: Some observations on stream.c and streamnt.c Cc: freebsd-security@FreeBSD.ORG In-reply-to: Your message of "Fri, 21 Jan 2000 21:26:39 MST." <4.2.2.20000121210443.01981600@localhost> References: <4.2.2.20000121210443.01981600@localhost> <4.2.2.20000120194543.019a8d50@localhost> <20000121162757.A7080@osaka.louisville.edu> <4.2.2.20000121195112.0196a220@localhost> Date: Fri, 21 Jan 2000 21:52:58 -0700 From: Warner Losh Sender: owner-freebsd-security@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org In message <4.2.2.20000121210443.01981600@localhost> Brett Glass writes: : during the call. When the user hangs up, your PPP software might want to : send a bunch of RSTs to shut down the caller's sessions (if it's been : tracking them). Or just do what a router does, and flag the machine : as down. I'm afraid I don't understand this. If the user disconnects, how can you send him RSTs? There's no connection. W/o ppp keeping state information, it can't send them to the other end. Also, it breaks lots of things. Really bad idea. : ICMP_BANDLIM isn't a very good fix for this exploit -- it merely limits some : of the secondary effects. Limiting or killing RSTs is much more effective. I have a patch that add RSTs to the mix, which does help a lot. : No, but it'll make it harder to figure out which 'sploits to try. It's the : difference between leaving the door visibly wide open and forcing the cracker : to TRY the door. If I can waste a cracker's time, I want to. Then why not have a strawman machine that responds in ways to make the hackers think it insecure, when in fact they are just yanking their chains :-) Warner To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-security" in the body of the message