GLSA-201603-04 : FUSE: incorrect filtering of environment variables leading to privilege escalation

low Nessus Plugin ID 89810

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-201603-04 (FUSE: incorrect filtering of environment variables leading to privilege escalation)

The fusermount binary calls setuid(geteuid()) to reset the RUID when it invokes /bin/mount so that it can use privileged mount options that are normally restricted if RUID != EUID. FUSE does not properly clear environment variables before invoking mount or umount as root allowing this to be passed to operations using elevated privileges such as LIBMOUNT_MTAB that is used by the mount commands debugging feature.
Impact :

The FUSE vulnerability allows a local, unprivileged user to overwrite arbitrary files on the system.
Workaround :

There is no known work around at this time.

Solution

All FUSE users should upgrade to the latest version:
# emerge --sync # emerge --ask --oneshot --verbose '>=sys-fs/fuse-2.9.4'

See Also

https://security.gentoo.org/glsa/201603-04

Plugin Details

Severity: Low

ID: 89810

File Name: gentoo_GLSA-201603-04.nasl

Version: 2.4

Type: local

Published: 3/10/2016

Updated: 1/11/2021

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: High

Score: 7.4

CVSS v2

Risk Factor: Low

Base Score: 3.6

Temporal Score: 3

Vector: CVSS2#AV:L/AC:L/Au:N/C:N/I:P/A:P

Vulnerability Information

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

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

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 3/9/2016

Exploitable With

Core Impact

Reference Information

CVE: CVE-2015-3202

GLSA: 201603-04