Bug 447048 (CVE-2012-5617)

Summary:	app-admin/gksu-polkit: privileged code execution with unprivileged credentials (CVE-2012-5617)
Product:	Gentoo Security	Reporter:	Agostino Sarubbo <ago>
Component:	Vulnerabilities	Assignee:	Gentoo Security <security>
Status:	RESOLVED INVALID
Severity:	trivial	CC:	gnome
Priority:	Normal
Version:	unspecified
Hardware:	All
OS:	Linux
URL:	http://www.openwall.com/lists/oss-security/2012/12/12/8
Whiteboard:
Package list:		Runtime testing required:	---

Description Agostino Sarubbo gentoo-dev

2012-12-12 22:33:30 UTC

From $URL :

This is a heads-up on a flaw reported to us regarding gksu-polkit.  This
was sent to the linux-distros@ mailing list last week.

Miroslav Trmac of Red Hat reported that gksu-polkit ships with an extremely
permissive PolicyKit policy configuration file.  Because gksu-polkit
allows a user to execute a program with administrative privileges, and
because the default allow_active setting is "auth_self" rather than
"auth_admin", any local user can use gksu-polkit to execute arbitrary
programs (like a bash shell) with root privileges.

For example:

$ cat foo.sh
#! /bin/bash
id -a
# not just gksu-polkit id -a because gksu-polkit tries to interpret the
# -a
# this prompts for user's password only
$ gksu-polkit /home/user/foo.sh
uid=0(root) gid=0(root) groups=0(root)
context=system_u:system_r:initrc_t:s0


(As an aside, I did some peeking because there was some discussion as to
whether or not this was intended behaviour.  It does not seem as though
gksu-polkit is intended to grant root access to every local user, even
though they need to actually be at the computer (I've not tested whether
or not this can be exploited via a remote X session, but it's possible).
Even if this is not remotely exploitable, we do tend to require
administrator authentication by local users (via su) or an administrator
to grant such privileges (via sudo), so to me this is definitely a
flaw).


References:

http://anonscm.debian.org/gitweb/?p=users/kov/gksu-polkit.git;a=blob;f=data/org.gnome.gksu.policy;h=ff0e4187941147d4f6c7ca53ebd1757521337288;hb=HEAD
https://bugzilla.redhat.com/show_bug.cgi?id=883162

Comment 1 Pacho Ramos gentoo-dev

2013-03-02 12:11:04 UTC

I am unsure if we are affected since we are applying auth_admin.patch from debian :/

Comment 2 Sean Amoss (RETIRED) gentoo-dev

2013-03-02 12:16:15 UTC

(In reply to comment #1)
> I am unsure if we are affected since we are applying auth_admin.patch from
> debian :/

Agreed! Thanks, Pacho.