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

high Nessus Plugin ID 19814

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.

Solution

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

See Also

https://security.gentoo.org/glsa/200509-15

Plugin Details

Severity: High

ID: 19814

File Name: gentoo_GLSA-200509-15.nasl

Version: 1.15

Type: local

Published: 10/5/2005

Updated: 1/6/2021

Risk Information

VPR

Risk Factor: Medium

Score: 5.9

CVSS v2

Risk Factor: High

Base Score: 7.2

Vector: AV:L/AC:L/Au:N/C:C/I:C/A:C

Vulnerability Information

CPE: p-cpe:/a:gentoo:linux:util-linux, cpe:/o:gentoo:linux

Required KB Items: Host/local_checks_enabled, Host/Gentoo/release, Host/Gentoo/qpkg-list

Patch Publication Date: 9/20/2005

Vulnerability Publication Date: 9/12/2005

Reference Information

CVE: CVE-2005-2876

GLSA: 200509-15