oss-sec mailing list archives

Re: CVE Request: rssh command-line parsing vulnerability


From: Kurt Seifried <kseifried () redhat com>
Date: Fri, 10 Aug 2012 23:03:30 -0600

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

On 08/10/2012 02:53 PM, Russ Allbery wrote:
Hello all,

I'm the Debian maintainer of the rssh package, which has a
security vulnerability in its command-line parsing disclosed some
time back on the rssh mailing list and on BUGTRAQ.  I'm preparing a
security update for Debian and would like a CVE for tracking
purposes.

The security advisory from the upstream maintainer is at: 
http://sourceforge.net/mailarchive/message.php?msg_id=29235647

Here are the relevant contents:

| 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... | [...] | | Note in particular that ensuring
that the AcceptEnv sshd configuration | option need not be turned
on for this exploit to work.

I think this would fit the definition of "local privilege
escalation" in that it allows users with a restricted shell to run
commands they shouldn't be able to run.

The last two messages on the thread linked above contain a patch.
(Be aware that they've been mangled by the Sourceforge mailing list
archive, so you have to download them to see them.)  There has been
no subsequent formal release, just the patch in that thread.

Not sure why I didn't get this a CVE earlier, please use CVE-2012-3478
for this issue. Red Hat reference:
https://bugzilla.redhat.com/show_bug.cgi?id=820414



- -- 
Kurt Seifried Red Hat Security Response Team (SRT)
PGP: 0x5E267993 A90B F995 7350 148F 66BF 7554 160D 4553 5E26 7993

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.12 (GNU/Linux)
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/
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=6Aoa
-----END PGP SIGNATURE-----


Current thread: