bugtraq - [ GLSA 200511-17 ] FUSE: mtab corruption through fusermount

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Date: Tue, 22 Nov 2005 17:45:59 +0100
From: Thierry Carrez <koon@...too.org>
To: gentoo-announce@...ts.gentoo.org
Cc: full-disclosure@...ts.grok.org.uk, bugtraq@...urityfocus.com,
	security-alerts@...uxsecurity.com
Subject: [ GLSA 200511-17 ] FUSE: mtab corruption through
	fusermount

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Gentoo Linux Security Advisory                           GLSA 200511-17
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
                                            http://security.gentoo.org/
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

  Severity: Normal
     Title: FUSE: mtab corruption through fusermount
      Date: November 22, 2005
      Bugs: #112902
        ID: 200511-17

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Synopsis
========

The fusermount utility from FUSE can be abused to corrupt the /etc/mtab
file contents, potentially allowing a local attacker to set
unauthorized mount options.

Background
==========

FUSE (Filesystem in Userspace) allows implementation of a fully
functional filesystem in a userspace program. The fusermount utility is
used to mount/unmount FUSE file systems.

Affected packages
=================

    -------------------------------------------------------------------
     Package      /  Vulnerable  /                          Unaffected
    -------------------------------------------------------------------
  1  sys-fs/fuse     < 2.4.1-r1                            >= 2.4.1-r1

Description
===========

Thomas Biege discovered that fusermount fails to securely handle
special characters specified in mount points.

Impact
======

A local attacker could corrupt the contents of the /etc/mtab file by
mounting over a maliciously-named directory using fusermount,
potentially allowing the attacker to set unauthorized mount options.
This is possible only if fusermount is installed setuid root, which is
the default in Gentoo.

Workaround
==========

There is no known workaround at this time.

Resolution
==========

All FUSE users should upgrade to the latest version:

    # emerge --sync
    # emerge --ask --oneshot --verbose ">=sys-fs/fuse-2.4.1-r1"

References
==========

  [ 1 ] CVE-2005-3531
        http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2005-3531

Availability
============

This GLSA and any updates to it are available for viewing at
the Gentoo Security Website:

  http://security.gentoo.org/glsa/glsa-200511-17.xml

Concerns?
=========

Security is a primary focus of Gentoo Linux and ensuring the
confidentiality and security of our users machines is of utmost
importance to us. Any security concerns should be addressed to
security@...too.org or alternatively, you may file a bug at
http://bugs.gentoo.org.

License
=======

Copyright 2005 Gentoo Foundation, Inc; referenced text
belongs to its owner(s).

The contents of this document are licensed under the
Creative Commons - Attribution / Share Alike license.

http://creativecommons.org/licenses/by-sa/2.0

Download attachment "signature.asc" of type "application/pgp-signature" (190 bytes)

_______________________________________________
Full-Disclosure - We believe in it.
Charter: http://lists.grok.org.uk/full-disclosure-charter.html
Hosted and sponsored by Secunia - http://secunia.com/