Date: Thu, 8 May 1997 08:12:44 -0700 (PDT) From: mfuhr@dimensional.com To: freebsd-gnats-submit@FreeBSD.ORG Subject: kern/3547: ktrace works even if no read permission Message-ID: <199705081512.IAA02039@hub.freebsd.org> Resent-Message-ID: <199705081520.IAA02398@hub.freebsd.org>
next in thread | raw e-mail | index | archive | help
>Number: 3547 >Category: kern >Synopsis: ktrace works even if no read permission >Confidential: no >Severity: non-critical >Priority: low >Responsible: freebsd-bugs >State: open >Class: sw-bug >Submitter-Id: current-users >Arrival-Date: Thu May 8 08:20:04 PDT 1997 >Last-Modified: >Originator: Michael Fuhr >Organization: Unspecified >Release: 2.2-STABLE >Environment: FreeBSD winnie.pooh.org 2.2-STABLE FreeBSD 2.2-STABLE #0: Wed May 7 19:19:10 MDT 1997 root@winnie.pooh.org:/usr/src/sys/compile/WINNIE-CDROM i386 >Description: Process tracing (options KTRACE) works on executables that have no read permission (--x--x--x), even for group or others. Read permission is usually turned off to keep users from knowing some information about how the program works or what files it accesses. Granted that security by obscurity isn't a good policy, but some people prefer to use it anyway, just to make the cracker's job a little harder. >How-To-Repeat: 1. Write a "hello, world" program in C and compile it. 2. Put the program in a world-accessible directory. 3. chmod 111 program 4. Run "ktrace program" as a different user. 5. Run "kdump" as the different user. >Fix: Haven't investigated thoroughly. Probably an additional check in kern/kern_trace.c, function ktrcanset(). >Audit-Trail: >Unformatted:
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199705081512.IAA02039>