FreeBSD Security Advisory FreeBSD-SA-18:05.ipsec
4 April, 2018 by firstname.lastname@example.org | freebsd
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 ============================================================================= FreeBSD-SA-18:05.ipsec Security Advisory The FreeBSD Project Topic: ipsec crash or denial of service Category: core Module: ipsec Announced: 2018-04-04 Credits: Maxime Villard Affects: All supported versions of FreeBSD. Corrected: 2018-01-31 09:24:48 UTC (stable/11, 11.1-STABLE) 2018-04-04 05:37:52 UTC (releng/11.1, 11.1-RELEASE-p9) 2018-01-31 09:26:28 UTC (stable/10, 10.4-STABLE) 2018-04-04 05:37:52 UTC (releng/10.4, 10.4-RELEASE-p8) 2018-04-04 05:37:52 UTC (releng/10.3, 10.3-RELEASE-p29) CVE Name: CVE-2018-6918 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 IPsec suite of protocols provide network level security for IPv4 and IPv6 packets. FreeBSD includes software originally developed by the KAME project which implements the various protocols that make up IPsec. In IPsec, the IP Authentication Header (AH) is used to provide protection against replay attacks and connectionless integrity and data origin authentication for IP datagrams. II. Problem Description The length field of the option header does not count the size of the option header itself. This causes a problem when the length is zero, the count is then incremented by zero, which causes an infinite loop. In addition there are pointer/offset mistakes in the handling of IPv4 options. III. Impact A remote attacker who is able to send an arbitrary packet, could cause the remote target machine to crash. IV. Workaround No workaround is available. Note that in FreeBSD 10 IPsec is not included in the kernel by default, but it is in FreeBSD 11. 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. Afterward, reboot the system. 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 Afterward, reboot the system. 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-18:05/ipsec.patch # fetch https://security.FreeBSD.org/patches/SA-18:05/ipsec.patch.asc # gpg --verify ipsec.patch.asc b) Apply the patch. Execute the following commands as root: # cd /usr/src # patch < /path/to/patch c) Recompile your kernel as described in <URL:https://www.FreeBSD.org/handbook/kernelconfig.html> and reboot the system. VI. Correction details The following list contains the correction revision numbers for each affected branch. Branch/path Revision - ------------------------------------------------------------------------- stable/10/ r328621 releng/10.3/ r331985 releng/10.4/ r331985 stable/11/ r328620 releng/11.1/ r331985 - ------------------------------------------------------------------------- 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-2018-6918> The latest revision of this advisory is available at <URL:https://security.FreeBSD.org/advisories/FreeBSD-SA-18:05.ipsec.asc> -----BEGIN PGP SIGNATURE----- iQKTBAEBCgB9FiEE/A6HiuWv54gCjWNV05eS9J6n5cIFAlrEZuRfFIAAAAAALgAo aXNzdWVyLWZwckBub3RhdGlvbnMub3BlbnBncC5maWZ0aGhvcnNlbWFuLm5ldEZD MEU4NzhBRTVBRkU3ODgwMjhENjM1NUQzOTc5MkY0OUVBN0U1QzIACgkQ05eS9J6n 5cKpOxAAlcyr88qHimXmMWNelNe+RvNkRoQwlmOw5XCWmWFGt4bX6KyrPSNVkZXK 9bZr0+sYiEjHPstXy+F6v95wqShRiefwpLVNJkP6LFKdQJeuxy0Uwsgl/i3aZVHy q4iM+PgnMwt5FxzmIcFHjwZSGGaOw5p9dMlkFLxXQ6chafPutMbgkXMIGVGXEp4e iwQgmh7j5LbUED0P9G7sYpcEN+DKZLWIyvz6L/AJmeHC/Z21TTeOoPjNPImgUmeU R2gK6WrQ5hfDvvFIJK1RvkR7OGdgrw0p2bCeeW8HRR5WEifO+a5Mb6+S414jWLYi uPYoxWf5NP92b9r3sLjNXbbsZ71mOZ49nZO3gc83O4mqOo9FYbTZ1W9C1UIO66pO bsp9e7g09gvT/VTO9j2Bu9nNdLd41Jx6NCmrrJAPP5fp7yhgtI7a+voF+swyBPSq kzSrNuY+PAnEvvAPzCz97uQQWabwbJoZNlPc+9IWZ7K++8N9j0K94dtsy8g6FMIT A54s3LX9X5v+EYEwqnbNgEZxkSgjgpQkbnQC3evBwVkSgm0aQb4jRXoe9aY6KGtA pSldkfyC364h8KNM1tbMq02fAIGDdBc+TbxjPabdc+FNmwVT+KlW/cBDy8J/rUhz BSyWQdVwjHZ45R4Vmf8pEDA4/uc/L7XnMuqwgn2gBe23riiAjDM= =WcBl -----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"