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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2016.0120 Insecure default bsnmpd.conf permissions 15 January 2016 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: bsnmpd Publisher: FreeBSD Operating System: FreeBSD Impact/Access: Access Privileged Data -- Existing Account Resolution: Patch/Upgrade CVE Names: CVE-2015-5677 Original Bulletin: https://www.freebsd.org/security/advisories/FreeBSD-SA-16:06.bsnmpd.asc - --------------------------BEGIN INCLUDED TEXT-------------------- - -----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----- iQIcBAEBCgAGBQJWl2j4AAoJEO1n7NZdz2rnkaQP/3K9kqYY1YoHQ++uzFPnfuZQ mkGPJ0frGG46pTL806QJidky6D0LP0zNCzhtU45ZlFMguJ3B3QYp/62Cw61dBG22 x0uEkvI2F2F39IPA/clspyUHg3Y1RYgTpJrxey0JLrK0yxelyI8vMwB4tCB2eEDW ZGVU6rvFQcWJOWHABXVYcc+4Yy5ucudp0QbJsVHAKLtF7MLuntVlUj+x4Nncog5k kmGt6W7tzFn2gNsWcmntmG/LWyPkPURWhYfIj3fgcRrpMTVIDFX5PTgQyJR7DwOM /beIoQxxKBUwTW1ZRgvcCqFBu7DKSCMABoHgpqLj1gdeiJ1LaO4dErtWXvdBEAAP +XLi5OkRG3OKzIAIRnkz/SrkAUoRkzHEK1dI0coyw7AdXXjDBWtX+n9lzRXs7hqT LC3riK/Km9OYVn3+T7tCWnvKN45f+FnD8zxZDE+33Jv9wI8X+CCs9GjJdoJ0HDSd b6rg8E4gGPzfwFxSNXZQKfDSSuVBECIp3av1gp6hN3qZNOX/sadMsxro8VVGFLPg 81rC+JfKNTeVtxF8oJi9eg3FQ/eupxQv4RvC2c37R7LcErAU1KKxZyNrwv6xDEMx QVnx74o+luxXSirLxq276pfBQJdMjxYzWCj6E8ztcAZenz3M4WNiRFlt7hdq/3YO bDBdQPe4eYSHHSGyGcz/ =LDPU - -----END PGP SIGNATURE----- - --------------------------END INCLUDED TEXT-------------------- You have received this e-mail bulletin as a result of your organisation's registration with AusCERT. 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It may not be updated when updates to the original are made. If downloading at a later date, it is recommended that the bulletin is retrieved directly from the author's website to ensure that the information is still current. Contact information for the authors of the original document is included in the Security Bulletin above. If you have any questions or need further information, please contact them directly. Previous advisories and external security bulletins can be retrieved from: http://www.auscert.org.au/render.html?cid=1980 =========================================================================== Australian Computer Emergency Response Team The University of Queensland Brisbane Qld 4072 Internet Email: auscert@auscert.org.au Facsimile: (07) 3365 7031 Telephone: (07) 3365 4417 (International: +61 7 3365 4417) AusCERT personnel answer during Queensland business hours which are GMT+10:00 (AEST). On call after hours for member emergencies only. =========================================================================== -----BEGIN PGP SIGNATURE----- Comment: http://www.auscert.org.au/render.html?it=1967 iQIVAwUBVphkqX6ZAP0PgtI9AQLbqA/+LQg9XutU0MZjK/3d6ww1Fm9cPYmq9/MJ 23EzFGwmMMDfJN8cWQ2Cm4RO2Z/5HkakUvYnhfFzzWzS8VccY66RheU0T7LyyEcA B5wGp0KqJtZYOthkyd8bs4DJodk5fAQmIiHMabBagEoyPab+h7AhdDabjnIUHw6F 4XmrxOeQtZWCsmlyVnfewnuXtP2Lp4z7q5LUlNi7rKPkJBM+FxHI3gnpYlb/PGxu HB9nV0KwPwkBAAgmhmA5LBXXDVMjXffKxEV9QePkdlcvf+/JSnWtOGA3o8Ynk4Yd IptzP52uVTxc8l9AxxJ30HNa0/rXwbnr6HUb+kDjXmdCBckb3PeFPuGZH8h+Uobo J00mmV6ZMJvA17OZIWyJLezfUwYV5JDn3hhsB5OPPh9V7NhEzkMBi7KWmvVoWkWx UpzEIAlhaF1bIPYYSHodnJ0u1f2/UirSR7Zgy7ay37xKSMUrPbLfJLD0Bh5/yOAO ETyA2/qfpJoch0en++5W2YvrzfwCgVSthgNJCN9HyNij1XZD5PAW0b5XUklVffC5 ftChHFc6E/oBZwYWzJW2O0017pbuhy7ML4+E2iEi1XzxwmTNsYW104p8ZKUguW0n ISs2RW1CJIqhCIaSbwP49lgia+dlnYPBTKKpJK0DJXd0sShc2LQBJvG6b17x/MMQ bvLK4kz+LAY= =Zkfr -----END PGP SIGNATURE-----