Re: rssh security announcement

All,

Today I released rssh-2.3.4, which fixes an old issue, and a new
issue:

On Tue, May 08, 2012 at 01:14:26PM -0500, Derek Martin wrote:
> rssh is a shell for restricting SSH access to a machine to only scp,
> sftp, or a small set of similar applications.
>
> http://www.pizzashack.org/rssh/
>
> Henrik Erkkonen has discovered that, through clever manipulation of
> environment variables on the ssh command line, it is possible to
> circumvent rssh. As far as I can tell, there is no way to effect a
> root compromise, except of course if the root account is the one
> you're attempting to protect with rssh…

This was CVE-2012-3478, for which I had originally only posted a patch
to the rssh mailing list. It is now fixed in the new release.

The new issue is CVE-2012-2252, which involves improper filtering of
the rsync command line, when rsync support is configured. This may be
somewhat of a non-issue for recent stock rssh installations, as
stock rssh does not support newer rsync binaries which use -e to
specify the rsync protocol; thus if you're using rssh with a recent
istallation, rsync does not work for you anyway, and you therefore
most likely have it disabled by config. Nevertheless, it is a
legitimate security concern if you have rsync enabled in the
configuration. This also is fixed in 2.3.4.

This release also includes some mostly trivial updates for the build
and a bit of minor code clean-up.

For people using rssh packages from Debian, Red Hat, or one of their
derivatives, a third vulnerability was recently discovered, assigned
CVE-2012-2251. This issue exists only in a third-party patch to make
rssh work with newer rsync binaries. Stock rssh is not vulnerable
to this issue. However if you are relying on your vendor to package
rssh, this likely affects you.

Lastly, since the vendors are providing their own packages, and I'm no
longer set up to build RPMs, I am no longer providing rssh in RPM
form. Please be sure to update rssh to v2.3.4, either by downloading
and compiling from the website, or by updating your vendor's packages.

http://www.pizzashack.org/rssh/downloads.shtml

Thank you.

– Derek D. Martin http://www.pizzashack.org/ GPG Key ID: 0x81CFE75D