lkml.org 
[lkml]   [2003]   [Nov]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRe: hard links create local DoS vulnerability and security problems
Date
On Monday 24 November 2003 19:08, splite@purdue.edu wrote:
> On Mon, Nov 24, 2003 at 06:57:41PM +0100, Jakob Lell wrote:
> > [...]
> > Setuid-root binaries also work in a home directory.
> > You can try it by doing this test:
> > ln /bin/ping $HOME/ping
> > $HOME/ping localhost
> > [...]
>
> That's why you don't put user-writable directories on the root or /usr
> partitions. (For extra points, mount your /tmp and /var/tmp partitions
> nodev,nosuid.) Seriously guys, this is Unix Admin 101, not a major new
> security problem.
Even if you put /usr on a separate partition, users can create a setuid (not
setuid-root) program in their home directory. Other users can create links to
this program in their home directory. Even if this can't be used to become
root, it shouldn't be possible. To prevent this, you have to put every user's
home directory on a separate partition.

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 13:58    [W:0.089 / U:7.376 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site