FreeBSD Security Advisory FreeBSD-SA-20:14.sctp
12 May, 2020 by firstname.lastname@example.org | freebsd
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 ============================================================================= FreeBSD-SA-20:14.sctp Security Advisory The FreeBSD Project Topic: Improper checking in SCTP-AUTH shared key update Category: core Module: kernel Announced: 2020-05-12 Credits: email@example.com Affects: FreeBSD 11.3 Corrected: 2019-09-19 10:01:19 UTC (stable/12, 12.1-STABLE) 2019-09-19 10:06:18 UTC (stable/11, 11.3-STABLE) 2020-05-12 16:55:32 UTC (releng/11.3, 11.3-RELEASE-p9) CVE Name: CVE-2019-15878 Note: The upcoming release of FreeBSD 11.4 was branched after the original commit to the stable branch and already includes the fix for this advisory. Similarly, the 12.1 branch was created shortly after the original commit to the stable branch and already includes the fix. 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 Stream Control Transmission Protocol (SCTP) is a transport protocol supporting the socket API. An SCTP packet consists of an SCTP common header and a number of SCTP chunks. The SCTP extension SCTP-AUTH can be used to authenticate SCTP chunks. It uses shared keys which can be managed via the socket API by the application using an SCTP association. II. Problem Description The SCTP layer does improper checking when an application tries to update a shared key. Therefore an unprivileged local user can trigger a use-after- free situation, for example by specific sequences of updating shared keys and closing the SCTP association. III. Impact Triggering the use-after-free situation may result in unintended kernel behaviour including a kernel panic. IV. Workaround No workaround is available. V. Solution Upgrade your vulnerable system to a supported FreeBSD stable or release / security branch (releng) dated after the correction date, and reboot. 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 # shutdown -r +10min "Rebooting for a security update" 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 https://security.FreeBSD.org/patches/SA-20:14/sctp.patch # fetch https://security.FreeBSD.org/patches/SA-20:14/sctp.patch.asc # gpg --verify sctp.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/12/ r352509 stable/11/ r352509 releng/11.3/ r360975 - ------------------------------------------------------------------------- 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-2019-15878> The latest revision of this advisory is available at <URL:https://security.FreeBSD.org/advisories/FreeBSD-SA-20:14.sctp.asc> -----BEGIN PGP SIGNATURE----- iQKTBAEBCgB9FiEE/A6HiuWv54gCjWNV05eS9J6n5cIFAl666WdfFIAAAAAALgAo aXNzdWVyLWZwckBub3RhdGlvbnMub3BlbnBncC5maWZ0aGhvcnNlbWFuLm5ldEZD MEU4NzhBRTVBRkU3ODgwMjhENjM1NUQzOTc5MkY0OUVBN0U1QzIACgkQ05eS9J6n 5cL7Gg/9GUkrcdpj9hxsSNTdjc4hnnyeMYAtkonQiak6BwrQQ5VgYMTbFDL3iw6b 4v4W8p/pANfeh8nk7h5Agfe39vUe3TuxFEuRn5aCOO/XuYfPYybhq74HrKTz61Iy LLmeExi+6nsWSIIJZVf1S2cyEc0qOV0fW1rE7Q9KQRSmbQF3i0HhUhPT0b8l/qJ9 tfVtkG3VYjWYF5HeV5WE1PyC0Y8pbrUNmZjbe7FxMilqMJ857eXcQqugrdqflri1 pJ5n8vHWy6OwNg8GVefb3Ht77dFBPlj2Kt02bjrA/ctLThBWPbtYgR+7S263TOnY tjeil+VkgOeeFcZLynbvGThE8/e/sl/G72JD7VtsEooVg+tfkIh83rJNCVaWxiEO u0+y+CmBpeD4ZZidOlqXr40WzpAtWTtnYCOn9eDJk3mn795B/GHpSPcH7RR57jr9 yU5lt0vCjktJY4in5VgTbikqD1369t0qZfLRPT84f1tC4AMTvpjG+AcGhwJfmFZL xQht9oXMWiW28J/Vt/AH5yFFGqEyJMNPl6zvqXSfgsKiMKka+5/FzeP1nFzlYEwG 6ygMm333Ur28l+eQ24nL1XpD8ydWXLnfF6N+onyIdH4c9rQ73omnvINmMBTJqEHC NOEJpmOdUFlX2ugzEqPxrVbGlH9s1I/+veuz+uYnGc3Q1Rtvl4c=h/Gp -----END PGP SIGNATURE----- _______________________________________________ firstname.lastname@example.org mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-announce To unsubscribe, send any mail to "email@example.com"