-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 ============================================================================= FreeBSD-SA-14:07.devfs Security Advisory The FreeBSD Project Topic: devfs rules not applied by default for jails Category: core Module: etc_rc.d Announced: 2014-04-30 Affects: FreeBSD 10.0 Corrected: 2014-04-30 04:03:05 UTC (stable/10, 10.0-STABLE) 2014-04-30 04:04:42 UTC (releng/10.0, 10.0-RELEASE-p2) CVE Name: CVE-2014-3001 For general information regarding FreeBSD Security Advisories, including descriptions of the fields above, security branches, and the following sections, please visit <URL:http://security.FreeBSD.org/>. I. Background The device file system, or devfs(5), provides access to kernel's device namespace in the global file system namespace. The devfs(5) rule subsystem provides a way for the administrator of a system to control the attributes of DEVFS nodes. Each DEVFS mount-point has a ``ruleset'', or a list of rules, associated with it, allowing the administrator to change the properties, including the visibility, of certain nodes. II. Problem Description The default devfs rulesets are not loaded on boot, even when jails are used. Device nodes will be created in the jail with their normal default access permissions, while most of them should be hidden and inaccessible. III. Impact Jailed processes can get access to restricted resources on the host system. For jailed processes running with superuser privileges this implies access to all devices on the system. This level of access could lead to information leakage and privilege escalation. IV. Workaround Systems that do not run jails are not affected. The system administrator can do the following to load the default ruleset: /etc/rc.d/devfs onestart Then apply the default ruleset for jails on a devfs mount using: devfs -m ${devfs_mountpoint} rule -s 4 applyset Or, alternatively, the following command will apply the ruleset over all devfs mountpoints except the host one: mount -t devfs | grep -v '^devfs on /dev ' | awk '{print $3;}' | \ xargs -n 1 -J % devfs -m % rule -s 4 applyset After this, the system administrator should add the following configuration to /etc/rc.conf to make it permanent, so the above operations do not have to be done each time the host system reboots. devfs_load_rulesets="YES" V. Solution Perform one of the following: 1) Upgrade your vulnerable system to a supported FreeBSD stable or release / security branch (releng) dated after the correction date. 2) 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 http://security.FreeBSD.org/patches/SA-14:07/devfs.patch # fetch http://security.FreeBSD.org/patches/SA-14:07/devfs.patch.asc # gpg --verify devfs.patch.asc b) Execute the following commands as root: # cd /usr/src # patch < /path/to/patch # install -o root -g wheel -m 444 etc/defaults/rc.conf /etc/defaults/ Follow the steps described in the "Workaround" section, or reboot the system. 3) 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 VI. Correction details The following list contains the correction revision numbers for each affected branch. Branch/path Revision - ------------------------------------------------------------------------- stable/10/ r265122 releng/10.0/ r265124 - ------------------------------------------------------------------------- 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:http://svnweb.freebsd.org/base?view=revision&revision=NNNNNN> VII. References <URL:http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2014-3001> The latest revision of this advisory is available at <URL:http://security.FreeBSD.org/advisories/FreeBSD-SA-14:07.devfs.asc> -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.22 (FreeBSD) iQIcBAEBCgAGBQJTYHsGAAoJEO1n7NZdz2rnXsQP/iInaOcBlBDIsZokdpQCgAoF eSKuD5ihYTnlUew9l7lsizOn9se8Lj692FOXWsAjVqodp+A+ew8mUYNBjrOZnPDq HMo/yV7iYHNMUFHOOa7baeUO5M84KIGwTvaWIhMtb7QsRIn3KkJaxBL75LbTjtAa odBrXv+/3K2aG0s7rVGtykmWaWmmo/fln27wtZTo0jzLikw3l/iSNsW7qy3RZWKh g48nf+yNlFPhUpcNnvtjdziw04aCT9KGLfJ8csY5inM5LgLs9TcXCYoHyFqyNWeD f0+dEbUDTp/ATppz6cCovjpFbBS6wKfg1k3JoVBNtrVOyu7+qgTQi58JnVpmLdBx s7msIWf/LlIiA9Jz0RKEdFbRBw1UVc45Zxse8gzVRnCxIwywFEuXDPQ0a3UxnQ1c Te0/QQ/rodS/WpELhhu3DGq3aONbznuP/NzQRSQpe1Oqr56+ATiiUo7ITXjm7fpW iqJ9I0BfeyrP/mI3cs2D8V6hOHqrlgdOSgoUwjpNcZCkO2yo/vl0Sk/NEhMhfHYO Wn3Dc/dQYwgFjqL1UW4WGKe/j/SW/JFLyb0+r/mIDq8Z2en1kBSHWBtvRu2hoFc+ mMZ2UpwxBXF71zeslajuGIZ/tfIsHmGLjj6BsRQcdbinEodwIJnlDb5y/KmsBV0w Yyigteth/aK/m3ikDCGs =qxER -----END PGP SIGNATURE----- _______________________________________________ [email protected] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-security To unsubscribe, send any mail to "[email protected]"