FreeBSD Security Advisory FreeBSD-SA-16:38.bhyve
6 December, 2016 by firstname.lastname@example.org | freebsd
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 ============================================================================= FreeBSD-SA-16:38.bhyve Security Advisory The FreeBSD Project Topic: bhyve(8) virtual machine escape Category: core Module: bhyve Announced: 2016-12-06 Credits: Felix Wilhelm Affects: FreeBSD 10.x, FreeBSD 11.0 Corrected: 2016-12-06 18:54:43 UTC (stable/11, 11.0-STABLE) 2016-12-06 18:49:38 UTC (releng/11.0, 11.0-RELEASE-p4) 2016-12-06 18:55:01 UTC (stable/10, 10.3-STABLE) 2016-12-06 18:49:48 UTC (releng/10.3, 10.3-RELEASE-p13) 2016-12-06 18:49:54 UTC (releng/10.2, 10.2-RELEASE-p26) 2016-12-06 18:49:59 UTC (releng/10.1, 10.1-RELEASE-p43) CVE Name: CVE-2016-1889 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 bhyve(8) is a hypervisor that supports running a variety of virtual machines (guests). II. Problem Description The bounds checking of accesses to guest memory greater than 4GB by device emulations is subject to integer overflow. III. Impact For a bhyve virtual machine with more than 3GB of guest memory configured, a malicious guest could craft device descriptors that could give it access to the heap of the bhyve process. Since the bhyve process is running as root, this may allow guests to obtain full control of the hosts they're running on. IV. Workaround No workaround is available, however, systems not using bhyve(8) for virtualization are not vulnerable. Additionally, systems using bhyve(8) with 3GB or less of configured guest memory are not vulnerable. V. Solution Upgrade your vulnerable system to a supported FreeBSD stable or release / security branch (releng) dated after the correction date. No reboot is needed. Rather the bhyve(8) process for vulnerable virtual machines should be restarted. 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 binary patch: Systems running a RELEASE version of FreeBSD on the amd64 platform can be updated via the freebsd-update(8) utility: # freebsd-update fetch # freebsd-update install 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. [FreeBSD 11.0, FreeBSD 10.3] # fetch https://security.FreeBSD.org/patches/SA-16:38/bhyve.patch # fetch https://security.FreeBSD.org/patches/SA-16:38/bhyve.patch.asc # gpg --verify bhyve.patch.asc [FreeBSD 10.2, FreeBSD 10.1] # fetch https://security.FreeBSD.org/patches/SA-16:38/bhyve-10.patch # fetch https://security.FreeBSD.org/patches/SA-16:38/bhyve-10.patch.asc # gpg --verify bhyve-10.patch.asc b) Apply the patch. Execute the following commands as root: # cd /usr/src # patch < /path/to/patch 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/10/ r309648 releng/10.1/ r309636 releng/10.2/ r309635 releng/10.3/ r309634 stable/11/ r309647 releng/11.0/ r309633 - ------------------------------------------------------------------------- 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-2016-1889> The latest revision of this advisory is available at <URL:https://security.FreeBSD.org/advisories/FreeBSD-SA-16:38.bhyve.asc> -----BEGIN PGP SIGNATURE----- iQIcBAEBCgAGBQJYRw1wAAoJEO1n7NZdz2rnepoP/1b6uXh8BFW8Qi9cVyfUkldC aRfAdmE3azyJCwTY2cipIA+qp9SJUxnLf1lPicERIPZY6iiC6Zm1Qi+cfwCvgczu ksY9aYOM7/v1jKuUrPf7tJZ5OokRzkL8W2uCKqAn2BODBK1mA4yy8yGthgyCT6bH JzvINPnlQzJKHCdp/8goRVITxa+kMF7UBbpPDAkHuBNKKNRLOYb50Z9G7BZp9/u6 /Y8avPVCOnU7WKDehG6FgyfE0Z+pUw6dAgpYNblsdQc148xGCSoHyHjXIX1jHzCv ZChUhj+6m7CQkjh/GG6x1Bz1lCcsIgsnPAAuQC0WqsaQRnUWJXjTyPMHwkxIHlD7 sFGPdM4RdMI0O95xMm9Dy05baNsAtBr6DExd48jFv/qbUio9FhUNUJ5rfQEAnyp2 aAZL34rd90KPFn5zp8EhskOPWGJp7lr+5FpV1m85R07qRES9875eWWYUW5H+yZK+ kwUcRKiYyvAFTx7Ag38pCtH4SVZ4zRV0mBZnOvchNosMSJz+tZYxApaXHY/nBJck wCr+v4DlB9x4LKt9CnB1ow+YqVsMuPyXwyj4e9Pyw/zkvW1aA/TJeUonmm1c2vI4 07b64wnTsvLGgbhN2ei8LPtAEwpN/DBn7D098Zwf4CfCGQ2VZQeC5AjyTSX9bvy/ WnKlRTDLDrFSpAD/1/Dz =ts3q -----END PGP SIGNATURE----- _______________________________________________ email@example.com mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-announce To unsubscribe, send any mail to "firstname.lastname@example.org"