From owner-freebsd-security@freebsd.org Wed Jul 8 21:07:04 2020 Return-Path: Delivered-To: freebsd-security@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 9FF6536F630 for ; Wed, 8 Jul 2020 21:07:04 +0000 (UTC) (envelope-from security-advisories@freebsd.org) Received: from freefall.freebsd.org (freefall.freebsd.org [96.47.72.132]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "freefall.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4B2Bh8251kz3yPK; Wed, 8 Jul 2020 21:07:04 +0000 (UTC) (envelope-from security-advisories@freebsd.org) Received: by freefall.freebsd.org (Postfix, from userid 945) id 1DE9817E8F; Wed, 8 Jul 2020 21:07:04 +0000 (UTC) From: FreeBSD Security Advisories To: FreeBSD Security Advisories Subject: FreeBSD Security Advisory FreeBSD-SA-20:20.ipv6 Reply-To: freebsd-security@freebsd.org Precedence: bulk Message-Id: <20200708210704.1DE9817E8F@freefall.freebsd.org> Date: Wed, 8 Jul 2020 21:07:04 +0000 (UTC) X-BeenThere: freebsd-security@freebsd.org X-Mailman-Version: 2.1.33 List-Id: "Security issues \[members-only posting\]" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 08 Jul 2020 21:07:04 -0000 -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 ============================================================================= FreeBSD-SA-20:20.ipv6 Security Advisory The FreeBSD Project Topic: IPv6 socket option race condition and use after free Category: core Module: network Announced: 2020-07-08 Credits: syzkaller, Andy Nguyen Affects: All supported versions of FreeBSD. Corrected: 2020-04-02 15:30:51 UTC (stable/12, 12.1-STABLE) 2020-07-08 20:11:40 UTC (releng/12.1, 12.1-RELEASE-p7) 2020-07-06 20:23:14 UTC (stable/11, 11.4-STABLE) 2020-07-08 20:11:40 UTC (releng/11.4, 11.4-RELEASE-p1) 2020-07-08 20:11:40 UTC (releng/11.3, 11.3-RELEASE-p11) CVE Name: CVE-2020-7457 For general information regarding FreeBSD Security Advisories, including descriptions of the fields above, security branches, and the following sections, please visit . I. Background The IPV6_2292PKTOPTIONS socket option allows user code to set IPv6 header options on a socket. II. Problem Description The IPV6_2292PKTOPTIONS set handler was missing synchronization, so racing accesses could modify freed memory. III. Impact A malicious user application could trigger memory corruption, leading to privilege escalation. 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-20:20/ipv6.patch # fetch https://security.FreeBSD.org/patches/SA-20:20/ipv6.patch.asc # gpg --verify ipv6.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 and reboot the system. VI. Correction details The following list contains the correction revision numbers for each affected branch. Branch/path Revision - ------------------------------------------------------------------------- stable/12/ r359565 releng/12.1/ r363026 stable/11/ r362975 releng/11.4/ r363026 releng/11.3/ r363026 - ------------------------------------------------------------------------- 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: VII. References The latest revision of this advisory is available at -----BEGIN PGP SIGNATURE----- iQKTBAEBCgB9FiEE/A6HiuWv54gCjWNV05eS9J6n5cIFAl8GLvVfFIAAAAAALgAo aXNzdWVyLWZwckBub3RhdGlvbnMub3BlbnBncC5maWZ0aGhvcnNlbWFuLm5ldEZD MEU4NzhBRTVBRkU3ODgwMjhENjM1NUQzOTc5MkY0OUVBN0U1QzIACgkQ05eS9J6n 5cJqxA/9H58yyRUSUy6BTRw0XkCQFO3r0NpTYPWK4RJFPWO2Jh5zL2QjxuSj3k9t zgJXM6a1RRgOxevxSzJJXD74BZz3XLJnC9T0tXsp3nikMrd+NSVN0g2jfAbx0l7R RFRUJOI2EfcGkIe0tZy4/nGr+H9eZiJt9a9vJ8DCoJuU9Ph/7w3GrVG+gbJfH4sV KhvhrRzla4ePadnHyQZALL5ov554BUa3dB9STz8zbdjt5yFREpvCJ9mIOHKNPBCR X5v7OMwhw++2Q0JtoMsmBHMi8zOkDpbjPk5eQNLHg3Iw9ZQrxW8KtM9Ru3KFtPw9 gisI9e53NkCUGLm9iq3oQG6CnCMulTMAlgN5f0HflEwy3vd7R/ibNLvx2yObmVOU cX1Nf0ydFfhoS/YQwArdGTUg12BlYL9lqiXTqojUBG+yikwA3XAIUJccpcYyZDLQ jR5N8Ct7fV9Ec5pdu4xkSQhKsto9pQVfS0Kabv7hlwumynVL+S7qsmS7FT3IC/4n FiXisrJr5TTNO8p/bIs8qooHYUkd06A5O8xy+gRDDPbgvYfevGWrd/vaHmiXpUsv dvv9ZnU8xlaSi66AEPs9kYw/WhF55deqaU1M0p6Ob3+TGyJIR3j3IPTAIIXSgTrq YiyvzqXM+ob3aysILYRv48LK7+5N/3hDU48FLUN6q1V99G7TV8o= =JUip -----END PGP SIGNATURE-----