Subject: Re: [vserver] Security issue: guest to host escape via TIOCSTI ioctl in vserver enter
From: halfdog <me@halfdog.net>
Date: Wed, 07 Nov 2012 21:53:02 +0000

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Herbert Poetzl wrote:
> On Wed, Nov 07, 2012 at 04:13:48PM +0000, halfdog wrote: Security 
> testing showed that when an admin enters a vserver guest from 
> interactive shell, a malicious user inside the guest can use this 
> to execute commands on the host. ...
> 
>> TIOCSTI only works if enabled for a guest (VXC_TIOCSTI) so
>> unless you have found a bug to circumvent this, I think
>> Linux-VServer is not affected.

That's strange, perhaps I made some mistake during testing with the
packages from repo.psand.net. Is VXC_TIOCSTI enabled by default, how
to check that it is really disabled. And did you try to run the
gdb-test? Were there any errors attaching to the process or during exec?

I'll try to run test-set again from completely fresh setup as soon as
possible. (or do you have a completely sane test environment available?)

> [1]
> http://www.halfdog.net/Security/2012/TtyPushbackPrivilegeEscalation/

- --
http://www.halfdog.net/
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