GLSA-200509-15 : util-linux: umount command validation error

This script is Copyright (C) 2005-2014 Tenable Network Security, Inc.


Synopsis :

The remote Gentoo host is missing one or more security-related
patches.

Description :

The remote host is affected by the vulnerability described in GLSA-200509-15
(util-linux: umount command validation error)

When a regular user mounts a filesystem, they are subject to
restrictions in the /etc/fstab configuration file. David Watson
discovered that when unmounting a filesystem with the '-r' option, the
read-only bit is set, while other bits, such as nosuid or nodev, are
not set, even if they were previously.

Impact :

An unprivileged user facing nosuid or nodev restrictions can
umount -r a filesystem clearing those bits, allowing applications to be
executed suid, or have device nodes interpreted. In the case where the
user can freely modify the contents of the filesystem, privilege
escalation may occur as a custom program may execute with suid
permissions.

Workaround :

Two workarounds exist, first, the suid bit can be removed from the
umount utility, or users can be restricted from mounting and unmounting
filesystems in /etc/fstab.

See also :

http://www.gentoo.org/security/en/glsa/glsa-200509-15.xml

Solution :

All util-linux users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose '>=sys-apps/util-linux-2.12q-r3'

Risk factor :

High / CVSS Base Score : 7.2
(CVSS2#AV:L/AC:L/Au:N/C:C/I:C/A:C)

Family: Gentoo Local Security Checks

Nessus Plugin ID: 19814 (gentoo_GLSA-200509-15.nasl)

Bugtraq ID:

CVE ID: CVE-2005-2876