FreeBSD Security Advisories
2020-Jul-08 21:07 UTC
FreeBSD Security Advisory FreeBSD-SA-20:19.unbound
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 ============================================================================FreeBSD-SA-20:19.unbound Security Advisory The FreeBSD Project Topic: Multiple vulnerabilities in unbound Category: contrib Module: unbound Announced: 2020-07-08 Affects: All supported versions of FreeBSD. Corrected: 2020-05-24 16:47:27 UTC (stable/12, 12.1-STABLE) 2020-07-08 20:25:06 UTC (releng/12.1, 12.1-RELEASE-p7) 2020-05-24 11:47:27 UTC (stable/11, 11.4-STABLE) 2020-07-08 20:22:38 UTC (releng/11.4, 11.4-RELEASE-p1) 2020-07-08 20:20:59 UTC (releng/11.3, 11.3-RELEASE-p11) CVE Name: CVE-2020-12662, CVE-2020-12663 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 Unbound is a validating, recursive, and caching DNS resolver. II. Problem Description Malformed answers from upstream name servers can send Unbound into an infinite loop, resulting in denial of service. A malicious query can cause a traffic amplification attack against third party authoritative nameservers. III. Impact Denial of service of the affected host, or of third parties via traffic amplification. IV. Workaround No workaround is available. Systems not running Unbound are not affected. V. Solution Upgrade your vulnerable system to a supported FreeBSD stable or release / security branch (releng) dated after the correction date. Perform one of the following: 1) 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 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. [FreeBSD 12.1] # fetch https://security.FreeBSD.org/patches/SA-20:19/unbound.12.1.patch # fetch https://security.FreeBSD.org/patches/SA-20:19/unbound.12.1.patch.asc # gpg --verify unbound.12.1.patch.asc [FreeBSD 11.4] # fetch https://security.FreeBSD.org/patches/SA-20:19/unbound.11.4.patch # fetch https://security.FreeBSD.org/patches/SA-20:19/unbound.11.4.patch.asc # gpg --verify unbound.11.4.patch.asc [FreeBSD 11.3] # fetch https://security.FreeBSD.org/patches/SA-20:19/unbound.11.3.patch # fetch https://security.FreeBSD.org/patches/SA-20:19/unbound.11.3.patch.asc # gpg --verify unbound.11.3.patch.asc b) Apply the patch. Execute the following commands as root: # cd /usr/src # patch -p0 < /path/to/patch c) Recompile the operating system using buildworld and installworld as described in <URL:https://www.FreeBSD.org/handbook/makeworld.html>. Restart the applicable daemons, or reboot the system. VI. Correction details The following list contains the correction revision numbers for each affected branch. Branch/path Revision - ------------------------------------------------------------------------- stable/12/ r361435 releng/12.1/ r363029 stable/11/ r361435 releng/11.4/ r363028 releng/11.3/ r363027 - ------------------------------------------------------------------------- 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://nlnetlabs.nl/downloads/unbound/CVE-2020-12662_2020-12663.txt> <URL:https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-12662> <URL:https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-12663> The latest revision of this advisory is available at <URL:https://security.FreeBSD.org/advisories/FreeBSD-SA-20:19.unbound.asc> -----BEGIN PGP SIGNATURE----- iQKTBAEBCgB9FiEE/A6HiuWv54gCjWNV05eS9J6n5cIFAl8GLldfFIAAAAAALgAo aXNzdWVyLWZwckBub3RhdGlvbnMub3BlbnBncC5maWZ0aGhvcnNlbWFuLm5ldEZD MEU4NzhBRTVBRkU3ODgwMjhENjM1NUQzOTc5MkY0OUVBN0U1QzIACgkQ05eS9J6n 5cLg3g/+KxaCk6wFvqDCYlT2Rx8ZfxuU4cG8anJvdanwI8pV7SWsVIilWvpIuW5Y 1P/TVmZiXpICToiUXdwaOMj8r/8QhmALXd3icb+QBUBdLlkm6Cuh/lSbEAyA63aF YYDF9FsXITVMcUCiUCxpVWSzDUW3LD5jMC/0jjvb7N0VhQyn4vHgEUa74jstnu4r 36QV1s+ucsJafwAyzfobP+fCGKnVM8rmJ/3jE/eifN9RajFJdlkTtV0j6ReK9XQR jWunCgYZs8Ur0RFu98hspeRsXPuygV83sDiVWPQUd+iKXC8fW52f+IpAVO4BB763 ZOjXaeudVfqorBXpKsldggEaCrxbJlEdwR9oZOrNww4QDqgPnU4Fkdb2TXyl5Gtx t0fbvEl2sxfx5M+3rF9ae++DPpmIiu8DiodF8XKfXicFZ2WpJmnwEY0SeEGYGyrO MJZW3i45qfe4CneFtt1r1v1feX3XQZKuyjtb++S2/PDiSQ1ZrkdE3Y3VYS3X+pLt C1ZFkw6nLDDSVzPiD+1i8VzRoKwS7zZKfAWMBJRiO3Jjh2vXsNRYO6wAMPq4HAvA DkB0Ykm0ioDqtUwEKhqAcJEmu6P44BM9SJ0ApFeKQ8L+isNoiaEMEVFG1HW9avl6 E+I33y5yBtvgrRiyqUvANh/ZYSb7FQDTf5rlUOwG+Pk/kUlMrUA=tonD -----END PGP SIGNATURE-----