From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 306 invoked by alias); 21 Jul 2013 19:43:11 -0000 Mailing-List: contact glibc-bugs-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Post: List-Help: , Sender: glibc-bugs-owner@sourceware.org Received: (qmail 29397 invoked by uid 48); 21 Jul 2013 19:41:08 -0000 From: "carlos at redhat dot com" To: glibc-bugs@sourceware.org Subject: [Bug libc/15755] CVE-2013-2207: pt_chown tricked into granting access to another users pseudo-terminal Date: Sun, 21 Jul 2013 19:43:00 -0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: glibc X-Bugzilla-Component: libc X-Bugzilla-Version: 2.18 X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: carlos at redhat dot com X-Bugzilla-Status: RESOLVED X-Bugzilla-Priority: P2 X-Bugzilla-Assigned-To: unassigned at sourceware dot org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: bug_status resolution Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-Bugzilla-URL: http://sourceware.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-SW-Source: 2013-07/txt/msg00133.txt.bz2 http://sourceware.org/bugzilla/show_bug.cgi?id=15755 Carlos O'Donell changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEW |RESOLVED Resolution|--- |FIXED --- Comment #2 from Carlos O'Donell --- commit e4608715e6e1dd2adc91982fd151d5ba4f761d69 Author: Carlos O'Donell Date: Fri Jul 19 02:42:03 2013 -0400 CVE-2013-2207, BZ #15755: Disable pt_chown. The helper binary pt_chown tricked into granting access to another user's pseudo-terminal. Pre-conditions for the attack: * Attacker with local user account * Kernel with FUSE support * "user_allow_other" in /etc/fuse.conf * Victim with allocated slave in /dev/pts Using the setuid installed pt_chown and a weak check on whether a file descriptor is a tty, an attacker could fake a pty check using FUSE and trick pt_chown to grant ownership of a pty descriptor that the current user does not own. It cannot access /dev/pts/ptmx however. In most modern distributions pt_chown is not needed because devpts is enabled by default. The fix for this CVE is to disable building and using pt_chown by default. We still provide a configure option to enable hte use of pt_chown but distributions do so at their own risk. -- You are receiving this mail because: You are on the CC list for the bug.