Twenty Year Anniversary

FreeBSD Security Advisory - FreeBSD-SA-16:06.bsnmpd

FreeBSD Security Advisory - FreeBSD-SA-16:06.bsnmpd
Posted Jan 15, 2016
Authored by Pierre Kim

FreeBSD Security Advisory - The SNMP protocol supports an authentication model called USM, which relies on a shared secret. The default permission of the bsnmpd configuration file, /etc/bsnmpd.conf, is weak and does not provide adequate protection against local unprivileged users. A local user may be able to read the shared secret, if configured and used by the system administrator.

tags | advisory, local, protocol
systems | freebsd
advisories | CVE-2015-5677
MD5 | fc7515d3e9f8630afb77d28bd7a61646

FreeBSD Security Advisory - FreeBSD-SA-16:06.bsnmpd

Change Mirror Download
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA512

=============================================================================
FreeBSD-SA-16:06.bsnmpd Security Advisory
The FreeBSD Project

Topic: Insecure default bsnmpd.conf permissions

Category: contrib
Module: bsnmpd
Announced: 2016-01-14
Credits: Pierre Kim
Affects: All supported versions of FreeBSD.
Corrected: 2016-01-14 09:11:42 UTC (stable/10, 10.2-STABLE)
2016-01-14 09:10:46 UTC (releng/10.2, 10.2-RELEASE-p9)
2016-01-14 09:11:16 UTC (releng/10.1, 10.1-RELEASE-p26)
2016-01-14 09:11:48 UTC (stable/9, 9.3-STABLE)
2016-01-14 09:11:26 UTC (releng/9.3, 9.3-RELEASE-p33)
CVE Name: CVE-2015-5677

For general information regarding FreeBSD Security Advisories,
including descriptions of the fields above, security branches, and the
following sections, please visit <URL:https://security.FreeBSD.org/>.

I. Background

The bsnmpd daemon serves the Internet SNMP (Simple Network Management
Protocol). It is intended to serve only the absolute basic MIBs and
implements all other MIBs through loadable modules.

II. Problem Description

The SNMP protocol supports an authentication model called USM, which relies
on a shared secret. The default permission of the bsnmpd configuration file,
/etc/bsnmpd.conf, is weak and does not provide adequate protection against
local unprivileged users.

III. Impact

A local user may be able to read the shared secret, if configured and used
by the system administrator.

IV. Workaround

No workaround is available, but systems that do not use bsnmpd with its USM
authentication model are not vulnerable.

V. Solution

This vulnerability can be fixed by modifying the permission on
/etc/bsnmpd.conf to owner root:wheel and permission 0600.

The patch is provided mainly for third party vendors who deploy FreeBSD
and provide a safe default. The patch itself DOES NOT fix the permissions
for existing installations.

The patch can be applied by performing one of the following:

1) Upgrade your vulnerable system to a supported FreeBSD stable or
release / security branch (releng) dated after the correction date.

The system administrator should change the permission on /etc/bsnmpd.conf
to root:wheel and 0600.

2) To update your vulnerable system via a binary patch:

Systems running a RELEASE version of FreeBSD on the i386 or amd64
platforms can be updated via the freebsd-update(8) utility:

# freebsd-update fetch
# freebsd-update install

The system administrator should change the permission on /etc/bsnmpd.conf
to root:wheel and 0600.

3) To update your vulnerable system via a source code patch:

The following patches have been verified to apply to the applicable
FreeBSD release branches.

a) Download the relevant patch from the location below, and verify the
detached PGP signature using your PGP utility.

# fetch https://security.FreeBSD.org/patches/SA-16:06/bsnmpd.patch
# fetch https://security.FreeBSD.org/patches/SA-16:06/bsnmpd.patch.asc
# gpg --verify bsnmpd.patch.asc

b) Apply the patch. Execute the following commands as root:

# cd /usr/src
# patch < /path/to/patch

c) Recompile the operating system using buildworld and installworld as
described in <URL:https://www.FreeBSD.org/handbook/makeworld.html>.

VI. Correction details

The following list contains the correction revision numbers for each
affected branch.

Branch/path Revision
- -------------------------------------------------------------------------
stable/9/ r293898
releng/9.3/ r293896
stable/10/ r293897
releng/10.1/ r293894
releng/10.2/ r293893
- -------------------------------------------------------------------------

To see which files were modified by a particular revision, run the
following command, replacing NNNNNN with the revision number, on a
machine with Subversion installed:

# svn diff -cNNNNNN --summarize svn://svn.freebsd.org/base

Or visit the following URL, replacing NNNNNN with the revision number:

<URL:https://svnweb.freebsd.org/base?view=revision&revision=NNNNNN>

VII. References

<URL:https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-5677>

The latest revision of this advisory is available at
<URL:https://security.FreeBSD.org/advisories/FreeBSD-SA-16:06.bsnmpd.asc>
-----BEGIN PGP SIGNATURE-----
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=LDPU
-----END PGP SIGNATURE-----

Comments

RSS Feed Subscribe to this comment feed

No comments yet, be the first!

Login or Register to post a comment

Want To Donate?


Bitcoin: 18PFeCVLwpmaBuQqd5xAYZ8bZdvbyEWMmU

File Archive:

May 2018

  • Su
  • Mo
  • Tu
  • We
  • Th
  • Fr
  • Sa
  • 1
    May 1st
    15 Files
  • 2
    May 2nd
    17 Files
  • 3
    May 3rd
    30 Files
  • 4
    May 4th
    29 Files
  • 5
    May 5th
    2 Files
  • 6
    May 6th
    3 Files
  • 7
    May 7th
    13 Files
  • 8
    May 8th
    27 Files
  • 9
    May 9th
    17 Files
  • 10
    May 10th
    15 Files
  • 11
    May 11th
    8 Files
  • 12
    May 12th
    2 Files
  • 13
    May 13th
    8 Files
  • 14
    May 14th
    7 Files
  • 15
    May 15th
    43 Files
  • 16
    May 16th
    19 Files
  • 17
    May 17th
    16 Files
  • 18
    May 18th
    15 Files
  • 19
    May 19th
    3 Files
  • 20
    May 20th
    7 Files
  • 21
    May 21st
    15 Files
  • 22
    May 22nd
    40 Files
  • 23
    May 23rd
    64 Files
  • 24
    May 24th
    55 Files
  • 25
    May 25th
    0 Files
  • 26
    May 26th
    0 Files
  • 27
    May 27th
    0 Files
  • 28
    May 28th
    0 Files
  • 29
    May 29th
    0 Files
  • 30
    May 30th
    0 Files
  • 31
    May 31st
    0 Files

Top Authors In Last 30 Days

File Tags

Systems

packet storm

© 2018 Packet Storm. All rights reserved.

Services
Security Services
Hosting By
Rokasec
close