Pd does a "seteuid(setuid())" to un-get root priveliges if run as setuid, after its priority gets promoted, so that it runs as the user who started it. But there are apparently loopholes, as Mathieu has found.
I'm trying to repeat Frank's trick with /etc/security/limits.conf, so far without success, but if that works it would be much preferable to making Pd setuid root.
cheers Miller
On Thu, Jul 12, 2007 at 10:40:49PM -0400, Hans-Christoph Steiner wrote:
On Jul 12, 2007, at 6:52 PM, Frank Barknecht wrote:
Hallo, Hans-Christoph Steiner hat gesagt: // Hans-Christoph Steiner wrote:
On Jul 12, 2007, at 3:18 PM, Mathieu Bouchard wrote:
Last year I demonstrated that it is possible to make a very small external that gives root access to the whole pd process. This vulnerability only affects Miller's pd, including pd-0.41-0test04 (which is the absolute latest). I have fixed that problem during devel_0_39 and carried it into the desiredata branch.
This problem is largely theoretical so far, as it requires an external to play with the setuid/seteuid commands. I can't think of any external that does that, except the small test that I made for the purpose of verifying my claim.
I haven't looked much for other possible breaches of root access.
This is only possible if you are running Pd as root, which is general is not a good idea. If Pd is running as a different user, then you wouldn't be able to gain root access.
Matju can comment better, but AFAIR in my tests his external also worked with a setuid root Pd started as a normal user. You can check this with the code, it's somewhere in the bug tracker.
Anyways, making /usr/bin/pd setuid is not necessary anyway, as I wrote in another mail.
"setuid root" means that the process will always run as root, no
matter who starts it. So it's the same as running pd as root..hc
Ciao
Frank Barknecht _ ______footils.org_ __goto10.org__
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