From owner-freebsd-questions Tue Feb 23 3:48:45 1999 Delivered-To: freebsd-questions@freebsd.org Received: from guepardo.vicosa.com.br (guepardo.tdnet.com.br [200.236.148.6]) by hub.freebsd.org (Postfix) with SMTP id 2A91E10F06 for ; Tue, 23 Feb 1999 03:48:35 -0800 (PST) (envelope-from grios@netshell.vicosa.com.br) Received: from netshell.vicosa.com.br [200.236.148.197] by guepardo.vicosa.com.br with ESMTP (SMTPD32-4.03) id AEB673D00B0; Mon, 22 Feb 1999 22:04:54 +03d00 Message-ID: <36D1FD47.C4BBAC6D@netshell.vicosa.com.br> Date: Mon, 22 Feb 1999 21:58:47 -0300 From: Gustavo Vieira G C Rios X-Mailer: Mozilla 4.5 [en] (Win95; I) X-Accept-Language: en MIME-Version: 1.0 To: Greg Lehey Cc: Dan O'Connor , freebsd-questions@FreeBSD.ORG Subject: Re: assembly References: <003001be5e98$8af7fb20$0200000a@danco.home> <36D1BAB6.BB3F8701@netshell.vicosa.com.br> <19990223092721.L93492@lemis.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG Very good answer, that's what a really want to know! Greg Lehey wrote: > > On Monday, 22 February 1999 at 17:14:46 -0300, Gustavo Vieira G C Rios wrote: > > Dan O'Connor wrote: > >> > >> From: Gustavo Vieira G C Rios > >> > >>> So no system is secure, if you have a shell account and an assembler to > >>> use, right ? > >> > >> You'd still have to have the proper file permissions to modify the > >> master.passwd file. Assembly language is just a low-level programming > >> language, not a security bypass. > > > > I don't believe (i am sorry if i am wrong, but i am a beginner)! > > If i use assembly i do not need to read a file via read API, i can > > access the HD directly, without to check for access permissions, > > right ? > > No. As I said in my last message, assembler doesn't bypass the API. > The system runs in two modes, user and kernel. The only way to load > kernel code without permission is to write your own kernel and boot > the machine with it. > > > If so, i can hack a UNIX system (no matter which) using assembly! > > No. > > > Am i wrong ? > > Yes. > > Greg > -- > When replying to this message, please copy the original recipients. > For more information, see http://www.lemis.com/questions.html > See complete headers for address, home page and phone numbers > finger grog@lemis.com for PGP public key -- I use UNIX because reboots are for hardware upgrades. You use windowze because the guy on TV told you to ... Gustavo Rios - UNIX System Admin. - UIN 27456973 +---------------------------------------------------+ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message