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Gentoo Linux Security Advisory GLSA 200511-17
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http://security.gentoo.org/
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Severity: Normal
Title: FUSE: mtab corruption through fusermount
Date: November 22, 2005
Bugs: #112902
ID: 200511-17
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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
=================
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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@gentoo.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
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