Messages in this thread | | | Date | Sun, 30 Apr 2006 11:37:41 +0200 | From | Willy Tarreau <> | Subject | Re: World writable tarballs |
| |
On Sun, Apr 30, 2006 at 09:15:01AM +0000, Heikki Orsila wrote: > On Sun, Apr 30, 2006 at 01:48:12AM +0100, Alistair John Strachan wrote: > > There's no need to repeatedly discuss it. > > I think there is. Sorry for wasting bandwidth. > > It's a big security hole deliberately caused by the kernel people (files > in the tar ball have og+w, so it's not problem in roots umask or tar). > Real security needs _simplicity_ but current file modes require > unnecessary _tricks_ for admins. There should be nothing against > untarring files as root. In this case it makes sense too, because only > the tar balls are crypto signed, not the individual files inside the tar > ball, so root can conveniently just verify the crypto signature and > untar the file without any race conditions or trusting other users. The > only real alternative is to create an _unnecessary_ trusted user to do > tar ball handling. > > PS. this file permission bug almost bit me. People make errors and this > one is potentially a big privilege escalation, because it potentially > turns normal application bugs into root privileges.
Although I don't like finding world-writable files in tar archives, I think you're exagerating a bit. First, you're not turning normal bugs into root privileges, and second, you don't need to create a user just for this, you just have to extract it in a directory that other users cannot access (chmod o-x).
Also, you'll find several other software on the net with full rights, so if this really is a concern to you, you'd better get used to this with simple and reliable solutions (ntp comes to mind).
> Heikki Orsila Barbie's law: > heikki.orsila@iki.fi "Math is hard, let's go shopping!" > http://www.iki.fi/shd
Regards, Willy
- 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/
| |