GLSA-201612-02 : DavFS2: Local privilege escalation

High Nessus Plugin ID 95517


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


The remote host is affected by the vulnerability described in GLSA-201612-02 (DavFS2: Local privilege escalation)

DavFS2 installs “/usr/sbin/mount.davfs” as setuid root. This utility uses “system()” to call “/sbin/modprobe”.
While the call to “modprobe” itself cannot be manipulated, a local authenticated user can set the “MODPROBE_OPTIONS” environment variable to pass a user controlled path, allowing the loading of an arbitrary kernel module.
Impact :

A local user could gain root privileges.
Workaround :

The system administrator should ensure that all modules the “mount.davfs” utility tries to load are loaded upon system boot before any local user can call the utility.
An additional defense measure can be implemented by enabling the Linux kernel module signing feature. This assists in the prevention of arbitrary modules being loaded.


All DavFS2 users should upgrade to the latest version:
# emerge --sync # emerge --ask --oneshot --verbose '>=net-fs/davfs2-1.5.2'

See Also

Plugin Details

Severity: High

ID: 95517

File Name: gentoo_GLSA-201612-02.nasl

Version: $Revision: 3.1 $

Type: local

Published: 2016/12/05

Modified: 2016/12/05

Dependencies: 12634

Risk Information

Risk Factor: High


Base Score: 7.2

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

Vulnerability Information

CPE: p-cpe:/a:gentoo:linux:davfs2, cpe:/o:gentoo:linux

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

Patch Publication Date: 2016/12/02

Reference Information

CVE: CVE-2013-4362

GLSA: 201612-02