From owner-freebsd-security Tue Aug 17 12: 6:56 1999 Delivered-To: freebsd-security@freebsd.org Received: from phoenix.aye.net (phoenix.aye.net [206.185.8.134]) by hub.freebsd.org (Postfix) with SMTP id B5EAB1576C for ; Tue, 17 Aug 1999 12:06:45 -0700 (PDT) (envelope-from barrett@phoenix.aye.net) Received: (qmail 395 invoked by uid 1000); 17 Aug 1999 18:59:55 -0000 Received: from localhost (sendmail-bs@127.0.0.1) by localhost with SMTP; 17 Aug 1999 18:59:55 -0000 Date: Tue, 17 Aug 1999 14:59:55 -0400 (EDT) From: Barrett Richardson To: Mike Tancsa Cc: freebsd-security@freebsd.org Subject: Re: Any work around for this FreeBSD bug/DoS ? In-Reply-To: <4.1.19990816203409.05989960@granite.sentex.ca> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-security@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org On Mon, 16 Aug 1999, Mike Tancsa wrote: > > Is there any work around or coming fix for the 'testsockbuf.c' originally > reported by Marc Olzheim on Aug 9th ? Its only a matter > of time until some wannabe script kiddie uploads it to one of my servers > for his/her cgi-script. It crashes 2.2.x and 3.x servers reliably :-( I > sent a message to the security officer last week but havent heard anything > since then. > > ---Mike > I've been using a mechanism that prevents the running the arbitrary executables on my systems. I require a flag bit to be set for an executable to be run -- so if script kiddie uploads or creates a binary executable it wont run, unless I approve it by setting the flag. At the moment I let shell scripts slide which will leave you vunerable to perl -- but that could be easily changed. When I set the flag for somebody, I also set the immutable flag so a user can't overwrite it with a binary of his choosing. I've relaxed the restriction for root to avoid administrative headaches. I've been mulling over the idea of making the behavior controllable via a sysctl mib on my systems, or adding it to one of the securelevels. Would be nicer if the securelevels were more fine grained like with a mask to turn on/off various things. What would be nice would be a bit to turn it on/off for users, a bit to turn it off/on for root and a bit to turn it off/on for shell scripts. The model with using the flag bit is imperfect, but can help out when you're in a pinch. - Barrett To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-security" in the body of the message