Re: [gentoo-hardened] qmailadmin, nosuid and tpe

[Petre Rodan]

hi,

On Thu, May 03, 2007 at 10:14:50PM +0200, Michael wrote:
> Hi all,
>
> On a hardened server which provides mail and web content I wanted to run
> qmailadmin. qmailadmin uses a binary in cgi-bin which is owned by user
> and group vpopmail, and has suid bit set. Before installing vpopmail I
> had my /var set to be mounted nosuid, because it'll be the first place
> any untrusted person might be able to have write access. So to make
> qmailadmin run from the cgi-bin I had to mount my /var without
> nosuid/with suid, which I'd like not to do, would there be any way
> around this?

AFAICT qmail is not even expected to run on a non-suid-ed /var. /var/qmail/bin/qmail-queue is a qmailq:qmail suid-ed binary.

and you should worry about /var/tmp not /var I guess.

> The next problem involves tpe (trusted path execution). I set up the
> wheel group as trusted group, so all other groups are untrusted. I think
> I might need to change this so a customer group will become untrusted
> and will contain the users that I don't trust, but if everything works
> this way (every group but wheel untrusted) I think that'd even be
> better... Now the problem is qmailadmin again... It's in the cgi-bin
> dir, which is owned by user and group apache, so apache has write access
> there. qmailadmin is owned by user and group vpopmail, so tpe says it's
> not safe for apache to execute qmailadmin. If I turn tpe off it works
> just fine, but of course I want tpe on.

you can add a different group just for TPE (not wheel) and as a worst case scenario set it as a supplementary group for all user id's that don't work well with it. but first try to tweak the unix permissions involved in the tpe denial.

bye,
peter

-- 
petre rodan
<kaiowas@g.o>
Developer,
Hardened Gentoo Linux