Actually I always do it via my fstab, typically with:
defaults,user,ro,noauto. But my experiments seemed to indicate that the
files still showed up as owned by root, with the s bit. However, I was
doing the experiment by just making the iso image and mounting via loop,
because I didn't want to waste too many cdrom blanks (I made an entry
for the iso file with the same options as /dev/cdrom, plus of course
loop).

So I'll try it for real. The scenario is: bad guy on own machine,
becomes root, makes an iso image with a malicious executable that's suid
root. Burns image. Pops disc into a target machine and mounts /dev/cdrom
as ordinary user. But it then shouldn't be possible to run that
executable with root permissions... right?

Judah


Ben Stern <[EMAIL PROTECTED]> wrote:

> On Wed, Jan 18, 2006 at 06:26:01PM +0000, Alexey Toptygin wrote:
> > Most people's fstab will mount CDs with one of the user[s], owner or group 
> > options. mount(8) says that they all imply noexec, nosuid and nodev. So I 
> > think that's "yes" and "probably not".
> 
> But not if you do "mount -o ro /dev/cdrom /mnt/cdrom" which is what I
> suspect Judah frequently does.
> 
> Ben
> -- 
> Ben Stern             UNIX & Networks Monkey             [EMAIL PROTECTED]
> This post does not represent FTI, even if I claim it does.  Neener neener.
> UM Linux Users' Group     Electromagnetic Networks      Microbrew Software

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