From owner-freebsd-security-notifications@freebsd.org Wed Sep 2 17:45:53 2020 Return-Path: Delivered-To: freebsd-security-notifications@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 6BCDA3DE679 for ; Wed, 2 Sep 2020 17:45:53 +0000 (UTC) (envelope-from security-advisories@freebsd.org) Received: from freefall.freebsd.org (freefall.freebsd.org [IPv6:2610:1c1:1:6074::16:84]) (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 4BhWZ92F7yz3bBt; Wed, 2 Sep 2020 17:45:53 +0000 (UTC) (envelope-from security-advisories@freebsd.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1599068753; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc; bh=XfaQ8J8+wfq5usNpWFUz4NucE+j6kJxpfLuRDFHBB+k=; b=p3q5C7a/FmLGEYt1s89nVl4NhbMw8lsr1vkG9cvD2XztyhTr0eVPseMhC9Wcd2kK+cTpA5 n3m7wL6V9FB59iZyRf5sdm9gbwkLasV0NgRPANYzHf3iDN0oVOcIuciYEorD8l7N3TIxMF G5AN/MqMpOnnG5mACZsqVY6PJosxsyCQHrSItvyZFxu1NqH7fwR4zblIyUeNvzmeUGu92D K0HhEX0yV8pUOfYGuk2Qd2a65SNZMqqnplXe2q28bPAtp1Cdx+Hwx5u/7WhddwIYn20fHc UrwuqtmZV5H3ea/vmyrf4js2eUNBrGRag9PSyvGIhdnIb6xfWmePHwonZoWJdw== Received: by freefall.freebsd.org (Postfix, from userid 945) id 454D1C9C1; Wed, 2 Sep 2020 17:45:53 +0000 (UTC) From: FreeBSD Security Advisories To: FreeBSD Security Advisories Subject: FreeBSD Security Advisory FreeBSD-SA-20:24.ipv6 Reply-To: freebsd-security@freebsd.org Precedence: bulk Message-Id: <20200902174553.454D1C9C1@freefall.freebsd.org> Date: Wed, 2 Sep 2020 17:45:53 +0000 (UTC) ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1599068753; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc; bh=XfaQ8J8+wfq5usNpWFUz4NucE+j6kJxpfLuRDFHBB+k=; b=UN/KHwROqnbNj7DSR7bKExVdacf1Kkgrj2K3mFgpjgm0sa2SMGJ9GOpalApN6JUM8q/eVI DWUWa2sYtw6vomkG/Q8h2SiWpLhccaq4OqERKJYyukCvHxUabmwM3e/GKz5QWxH5nNM53/ FoSd+koifAr9qlE3HuNU/5tF0Jd93qlS05ReOkYD1eKU2qeGp1ytswDe4nFlHzKr3HZZMz xf4Z9rNDi/5sgMJuZZBNH1mJYye4AgkcQynZhPbLsXPMskYTibEx9FGcYrfAxt2aRvuB3U HvDid50F/Of590cWdtuR7EkA3DvDz8w4m0SBozMdsvnZEf9nSiQXV0Fw/ey04Q== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1599068753; a=rsa-sha256; cv=none; b=W6aYMCHVQByqSJcPISx2klZbwHYPiyFZXO/g4HimdgYzpTxK8U5c2f0AQPBZa4tA/1/fj1 Qj8LKzJ6LU4+QE3SOTYujRltqykJi7CPMpMfVJfXX4foGXPd4V/rKXUtMn1gkg1bVDM0l1 yX4EkUKy6YniC2PmX/W+3dNVvV02LfCrU2a8qrr0FWxLdGcCdBJEpufnnLflkgHzQB3E1B XoQAlPeO9tzEUOQgcgqYGc2OJjsw8bdKeb173Wd9fvBY+ngX7Y5/jgWXOCBYZuFiD+ShBq khxHcGHqu3okGQmIERjZtoqHQzFJmet4THCVAkEzMQF8Kqm3N4cLuUR3hCfvfg== ARC-Authentication-Results: i=1; mx1.freebsd.org; none X-BeenThere: freebsd-security-notifications@freebsd.org X-Mailman-Version: 2.1.33 List-Id: "Moderated Security Notifications \[moderated, low volume\]" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 02 Sep 2020 17:45:53 -0000 -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 ============================================================================= FreeBSD-SA-20:24.ipv6 Security Advisory The FreeBSD Project Topic: IPv6 Hop-by-Hop options use-after-free bug Category: core Module: kernel Announced: 2020-09-02 Affects: FreeBSD 11.3 Corrected: 2020-05-07 01:28:59 UTC (stable/11, 11.4-PRERELEASE) 2020-09-02 16:23:15 UTC (releng/11.3, 11.3-RELEASE-p13) CVE Name: CVE-2020-7462 For general information regarding FreeBSD Security Advisories, including descriptions of the fields above, security branches, and the following sections, please visit . I. Background IPv6 is a network layer supporting Hop-by-Hop options, which can be sent by applications via the socket API. The memory management for packet handling is done using mbufs. II. Problem Description Due to improper mbuf handling in the kernel, a use-after-free bug might be triggered by sending IPv6 Hop-by-Hop options over the loopback interface. 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-20:24/ipv6.patch # fetch https://security.FreeBSD.org/patches/SA-20:24/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/11/ r360733 releng/11.3/ r365255 - ------------------------------------------------------------------------- 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/A6HiuWv54gCjWNV05eS9J6n5cIFAl9PzTNfFIAAAAAALgAo aXNzdWVyLWZwckBub3RhdGlvbnMub3BlbnBncC5maWZ0aGhvcnNlbWFuLm5ldEZD MEU4NzhBRTVBRkU3ODgwMjhENjM1NUQzOTc5MkY0OUVBN0U1QzIACgkQ05eS9J6n 5cLJYxAAotGAWrawa3gRK8gVpEIJiYknR9bODjDojm7KovlkuKeYAkyQ92/Ii23U U6tMXSPDYQFyscOdrGq4yEjxRDLLkGQGynQpioinDn8POKX7BKpy+PFFdv1mmBef h/WpgmlPdhymYisaImgVyGAxU81auzpFB6mArzFDCdHavTd7jVD2lJwcpdzeOk// NHOsj8C4VYJs0XcYrNa4CEWfH/D/uNO8u2b3QUfKQSOdfIfaDv22k2b96YKm+zcr xS7Q1jDv7QBTQou7KNOfoPi0Gclp8Q9VReP2nY/hB5TmJjR3irz+Z6UcGfiyDGrL XRB7oP23jIUmBbsINUN06FIhAPGF9/7zcOOoV1YOdwvmbLM0/W4c+mERZ16gw6+N MzCLDOeiyKAUr+pQzcl6lORxr31eB8400l6nRJwmCiWx4nHwyHPIl1RtfvsdNqfE /OBVEalxsCrzStfW4ME5RziPo9Y8DrajPf7+JY/4CIV3v/dJAiGi3+qs9Zn8enar WCR/8+o4xbT+d1sGTG1W3Qjh9a28jxqEusLjdehDy8PTk9OnIfPRuxj+kvot3Wo0 lWdeSIo8YZPYn7hG9N19k6aDlljM1fgkBmWj1uELtCeIE7WM5tHGMBuaS0cTt1jL s2g01qgkgW2a6cChdm3oNfUKE5KpD3/hU63/jEA6QyJJQQqXlOs= =kFlz -----END PGP SIGNATURE----- From owner-freebsd-security-notifications@freebsd.org Wed Sep 2 17:45:58 2020 Return-Path: Delivered-To: freebsd-security-notifications@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 B40863DE922 for ; Wed, 2 Sep 2020 17:45:58 +0000 (UTC) (envelope-from security-advisories@freebsd.org) Received: from freefall.freebsd.org (freefall.freebsd.org [IPv6:2610:1c1:1:6074::16:84]) (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 4BhWZG3d0dz3bHT; Wed, 2 Sep 2020 17:45:58 +0000 (UTC) (envelope-from security-advisories@freebsd.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1599068758; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc; bh=B+JyZ1omRR/4OG3IUGrw8uGoMffGrzMCvg1PmGCd5Oo=; b=BNwb86kJxsEJW9rEFUaJtRnSUb0xergIVJTOOG53mFy4Uz5Fn+bCQ7IpdTwBT0uR2IsJTY OhYibO2bD6sA4toyBkgfrgUcaYZOF9AICZyF7/zeyNWvgzF6YYxndmujWMDj2+3KCMu0Ux 4ypcIFZ1DmodwfeKKNdX/4TDjr5spRK1YQQBniAPcRtRpxorjnULjTtceV6KM8htGPlyDm 9WQk0mVtqC6R9UC2ZSDcJuHkrYeQD0sMqdP0Jmn3yD6kwhK86dW9qkG8k1NznyVE06a+Dc ztnllCaIbGSeToioCUwJet2bVNZT0WV7hEbg8HpBlQe6pohWEzTSO3kQ5tTVWQ== Received: by freefall.freebsd.org (Postfix, from userid 945) id 3DD91CA8D; Wed, 2 Sep 2020 17:45:58 +0000 (UTC) From: FreeBSD Security Advisories To: FreeBSD Security Advisories Subject: FreeBSD Security Advisory FreeBSD-SA-20:25.sctp Reply-To: freebsd-security@freebsd.org Precedence: bulk Message-Id: <20200902174558.3DD91CA8D@freefall.freebsd.org> Date: Wed, 2 Sep 2020 17:45:58 +0000 (UTC) ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1599068758; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc; bh=B+JyZ1omRR/4OG3IUGrw8uGoMffGrzMCvg1PmGCd5Oo=; b=Hp1rxLpFbNPzPW8x/gUzu5Esi52ELSaKTnvffI/FfEGmBZ3guHTb0vwAdTFDJXjZuBn/DX E+vPUqud2Z6ru9dBDPZE6auDTXon4vdRREewKDoNp0W4mCE+MBoS+vZvr+QzYBmurJSAI+ 57QSaUE+jZ7dJkORH5fCZuVDBHLALH1hXx1q86091EhHrjrFJj7I+fDGSLKIreCGynWEEE FF2Ig3dSqR1ueJvz8f0D+ufVRBMblkZ6XYozFSLa3Bh5AbR94/Udh97qJgdFIIeTieYpXS Co9zJnua9DEs8e8NyI82zbJdSGwQOl+PrLVlryR8O13iZD3/c/47dBCa3zb0fQ== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1599068758; a=rsa-sha256; cv=none; b=oISrOxqBFv9q7IgHuvHSfVthUR01JawlrACRyUnUj0AmfSeBM9xKShqYAhhssdfi0O0891 9jcXn6jQwSntac39lSR1nhhTMUSVZWWGdwnJHVTRDSY06eniYb6/1mOyaXSQFQe3QpWSch HDv063Ae6cGxCKwOKfCHY5KHXdJXS3DpSpih6GYcfEiU06R/zFGXki3LALJe9qj6V5Oapn AvkGJP41Tr2WjP88ZJUMk9XiNHtFrTqBlW8O1fVWK4ea/IMHopEJgLcUmzyueLJJo9YI4l BOEbfExhykSRKodRTDRFKvafeDl+PeuVkzmAg/UjZKzQLe2QohhKS8qWOOpcTg== ARC-Authentication-Results: i=1; mx1.freebsd.org; none X-BeenThere: freebsd-security-notifications@freebsd.org X-Mailman-Version: 2.1.33 List-Id: "Moderated Security Notifications \[moderated, low volume\]" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 02 Sep 2020 17:45:59 -0000 -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 ============================================================================= FreeBSD-SA-20:25.sctp Security Advisory The FreeBSD Project Topic: SCTP socket use-after-free bug Category: core Module: kernel Announced: 2020-09-02 Credits: Megan2013678@protonmail.com Affects: All supported versions of FreeBSD. Corrected: 2020-08-24 09:19:05 UTC (stable/12, 12.1-STABLE) 2020-09-02 16:24:32 UTC (releng/12.1, 12.1-RELEASE-p9) 2020-08-24 09:46:36 UTC (stable/11, 11.4-STABLE) 2020-09-02 16:24:32 UTC (releng/11.4, 11.4-RELEASE-p3) 2020-09-02 16:24:32 UTC (releng/11.3, 11.3-RELEASE-p13) CVE Name: CVE-2020-7463 For general information regarding FreeBSD Security Advisories, including descriptions of the fields above, security branches, and the following sections, please visit . I. Background The Stream Control Transmission Protocol (SCTP) is a message oriented transport protocol supporting arbitrary large user messages. It can be accessed from applications by using the the socket API. II. Problem Description Due to improper handling in the kernel, a use-after-free bug can be triggered by sending large user messages from multiple threads on the same socket. 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. [FreeBSD 12.1] # fetch https://security.FreeBSD.org/patches/SA-20:25/sctp.12.1.patch # fetch https://security.FreeBSD.org/patches/SA-20:25/sctp.12.1.patch.asc # gpg --verify sctp.12.1.patch.asc [FreeBSD 11.4] # fetch https://security.FreeBSD.org/patches/SA-20:25/sctp.11.4.patch # fetch https://security.FreeBSD.org/patches/SA-20:25/sctp.11.4.patch.asc # gpg --verify sctp.11.4.patch.asc [FreeBSD 11.3] # fetch https://security.FreeBSD.org/patches/SA-20:25/sctp.11.3.patch # fetch https://security.FreeBSD.org/patches/SA-20:25/sctp.11.3.patch.asc # gpg --verify sctp.11.3.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/ r364644 releng/12.1/ r365256 stable/11/ r364651 releng/11.4/ r365256 releng/11.3/ r365256 - ------------------------------------------------------------------------- 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/A6HiuWv54gCjWNV05eS9J6n5cIFAl9PzTZfFIAAAAAALgAo aXNzdWVyLWZwckBub3RhdGlvbnMub3BlbnBncC5maWZ0aGhvcnNlbWFuLm5ldEZD MEU4NzhBRTVBRkU3ODgwMjhENjM1NUQzOTc5MkY0OUVBN0U1QzIACgkQ05eS9J6n 5cIMPw//ZOYh7TQdwvreQ/iZbJphPp7hBVJqFWPE9M72Yfo87/vkl+T5/GW9wiLT MQlknQ7SDyzE7i8RpGvX0lmXLbr1e2rkvin1ZFdCbWkPzC7w0WVH7XX6+I+RJmkh E4dtmHrYhLRwmVtW5WYZdfO+iYVTJl/h43eYbYvNgJZSuKkvl2Vk6DqyseHx7xR6 gc7/41AIpMiqRLQI9ZnRvZCEiLq4G+q5z499ACfAutT9o+1T9L6QLCPuyY+fziiq cI2E/pQA5uxOY/z3ejKHeOzErjycY6GEhMiBKmsJqV6oU/cZd5hZ1qsmE9Xbi3/c Ax+OZr+Ve2a78dD7jOrmCrpBtG1Pg39c6VuQqHD3UN3seBNEkn4kto9vDX9fLceD GZbueV97boFxjnXu1B6C8ufqEZDqTaf/SU3+vCobBgydP+V8c1P5LbP6qcFHOUrk k7ijiJv03aYyY1Z6XtqbRsudZzIaTt+jneUA1eA46iWQqVZQHKo2liw5kAtsGu0k injGcazWRphV6xgOHIMCfrGcLLf0j+4UjiDUk30cansLGewuk/uEh6FlA4NzyRWA 4L3Q0l/XQWvO2sNMtF9LbBUUujDyy93Vy8BouSp59v7+bAYrRHfcIAmaQnE4jev2 BY7/JsrfQ9rG/Anzg49Hec8pw9VEvv4kA1STqXcpMt9Fq+0DslA= =2ET6 -----END PGP SIGNATURE----- From owner-freebsd-security-notifications@freebsd.org Wed Sep 2 17:46:04 2020 Return-Path: Delivered-To: freebsd-security-notifications@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 85A523DEA2C for ; Wed, 2 Sep 2020 17:46:04 +0000 (UTC) (envelope-from security-advisories@freebsd.org) Received: from freefall.freebsd.org (freefall.freebsd.org [IPv6:2610:1c1:1:6074::16:84]) (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 4BhWZM5f0Vz3b2K; Wed, 2 Sep 2020 17:46:03 +0000 (UTC) (envelope-from security-advisories@freebsd.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1599068764; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc; bh=hiRsugYPJy1sq0ut/ZvHuE7PwGuNJXYoiAnGaL8jmkQ=; b=atQVshWhpU4ZBYM9L3+Pg8ILq8ZwE9ZgrDNQVjpYmLqoY9/Izz2xDbbfDiO85ZZLk0nJKd BPAFA5oKelMhz8lHiApRwecT9oRBK8qTR/oEWMcgzp/QW0M74QeIKGw0ER4fV8f99zDDol +v+ztIZSRPuqAMDxYAMLdZspAChgzCafF4INgWVfgDUW9rq8A8vgi4ne5UE96OlUw/Hn2P WEug9vwOGvCdm7YAYNxxtkEPGQpxPtGhmsWgEak4O5og3foAHb2WT+LY5uc3BHmfW9DUQm jbQ1tDQySe1XGeJEv6LXfLjXvVHRaXe79en66g/9ZCBtTm9QZFUjZRIikAdJaQ== Received: by freefall.freebsd.org (Postfix, from userid 945) id 9C4F9CA95; Wed, 2 Sep 2020 17:46:03 +0000 (UTC) From: FreeBSD Security Advisories To: FreeBSD Security Advisories Subject: FreeBSD Security Advisory FreeBSD-SA-20:26.dhclient Reply-To: freebsd-security@freebsd.org Precedence: bulk Message-Id: <20200902174603.9C4F9CA95@freefall.freebsd.org> Date: Wed, 2 Sep 2020 17:46:03 +0000 (UTC) ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1599068764; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc; bh=hiRsugYPJy1sq0ut/ZvHuE7PwGuNJXYoiAnGaL8jmkQ=; b=JMs0eNJDMPLFhvxMoQbjRibso/3c3zznrkNxuP6qSDFvQpKyn4v1HO7Zc4ZbJ9nbGc1VsU SB0/T6C5D+CDdaAnxrVY8P4cdVujuEhS66Swj6d5ZBIxmqdt76R9xPmT4eIz/mikjtWVJE YzUSpfJj8AmH9iUuQnFhgIDKVEGtlYFaw2OyrhTjGlcwGBkF92ihSHLyD80xpFIxaTN4Ia TKsg1dEuUocfP0wd1bvR4D43ru2DOnC8U6rR8NNVu4yWb++iKthcDY7o92xbyg+K82tRiu 879NTl9t7oOF6h/WSOZkmV4Egs7YgfNuFUsO9i8/LTSXrENAvXZnMrVDmKFugQ== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1599068764; a=rsa-sha256; cv=none; b=Z3Zzc0vx9NvFGz+FmO9K0IXuErlY4Qm+tAOMR5GNCcehMAPwGFNuHktdah7fygdaLnn2b+ XxLelaybM3gw/vUVA4PbQFqV0TN3bQuWdB73L8Ylwx3iJuKZ4kYuImfO1MewsPYiSOcyzG CAkIeYHfPkYMbfkw7t/xtkBIPDa8sSxUyD23I00HI3lDb9w11N85Iizg0AqLSrSDSJmeIm /EQP06IkJHEfc5yTLkiJ8TCozmiY6z3abruGEgvCYDZt3CbVtMvzWdSwCXOALLC/Zfi9DN D7MFpnwHh1WT5KWpc23siOpP4/w+7Oc/M8bAUE0gsRtsSTP8uCLC8dyf+QMLRg== ARC-Authentication-Results: i=1; mx1.freebsd.org; none X-BeenThere: freebsd-security-notifications@freebsd.org X-Mailman-Version: 2.1.33 List-Id: "Moderated Security Notifications \[moderated, low volume\]" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 02 Sep 2020 17:46:04 -0000 -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 ============================================================================= FreeBSD-SA-20:26.dhclient Security Advisory The FreeBSD Project Topic: dhclient heap overflow Category: core Module: dhclient Announced: 2020-09-02 Credits: Shlomi Oberman, JSOF Affects: All supported versions of FreeBSD. Corrected: 2020-08-31 21:28:09 UTC (stable/12, 12.1-STABLE) 2020-09-02 16:25:31 UTC (releng/12.1, 12.1-RELEASE-p9) 2020-08-31 21:28:57 UTC (stable/11, 11.4-STABLE) 2020-09-02 16:25:31 UTC (releng/11.4, 11.4-RELEASE-p3) 2020-09-02 16:25:31 UTC (releng/11.3, 11.3-RELEASE-p13) CVE Name: CVE-2020-7461 For general information regarding FreeBSD Security Advisories, including descriptions of the fields above, security branches, and the following sections, please visit . I. Background dhclient(8) is the default IPv4 DHCP client used on FreeBSD. It is responsible for contacting DHCP servers on a network segment, and for initializing and configuring network interfaces and configuring name resolution based on received information. dhclient(8) handles DHCP option 119, the Domain Search Option, which provides a list of domains to search when resolving names using DNS. The option data format uses a compression scheme to avoid transmitting duplicate domain name labels. II. Problem Description When parsing option 119 data, dhclient(8) computes the uncompressed domain list length so that it can allocate an appropriately sized buffer to store the uncompressed list. The code to compute the length failed to handle certain malformed input, resulting in a heap overflow when the uncompressed list is copied into in inadequately sized buffer. III. Impact The heap overflow could in principle be exploited to achieve remote code execution. The affected process runs with reduced privileges in a Capsicum sandbox, limiting the immediate impact of an exploit. However, it is possible the bug could be combined with other vulnerabilities to escape the sandbox. IV. Workaround No workaround is available. To trigger the bug, a system must be running dhclient(8) on the same network as a malicious DHCP server. V. Solution Upgrade your vulnerable system to a supported FreeBSD stable or release / security branch (releng) dated after the correction date, and restart dhclient or 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-20:26/dhclient.patch # fetch https://security.FreeBSD.org/patches/SA-20:26/dhclient.patch.asc # gpg --verify dhclient.patch.asc b) Apply the patch. Execute the following commands as root: # cd /usr/src # patch < /path/to/patch c) Recompile the operating system using buildworld and installworld as described in . 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/ r365010 releng/12.1/ r365257 stable/11/ r365011 releng/11.4/ r365257 releng/11.3/ r365257 - ------------------------------------------------------------------------- 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/A6HiuWv54gCjWNV05eS9J6n5cIFAl9PzTtfFIAAAAAALgAo aXNzdWVyLWZwckBub3RhdGlvbnMub3BlbnBncC5maWZ0aGhvcnNlbWFuLm5ldEZD MEU4NzhBRTVBRkU3ODgwMjhENjM1NUQzOTc5MkY0OUVBN0U1QzIACgkQ05eS9J6n 5cLLPxAAhg/FSqWLykYAiQ8czoy98X00VIWAP1f4InfUKm8qOB8/7ptzv3A+2Hov 7lHlyN0D4OwhJFt7fw9oTwNe4UgxShso6QrezaTJZR7juFELy9WODbRFnNK4i8w9 NCBab+NIn1o7nFZnB0M5TMKfa4gc1jAV+Q/U/zi+ONvwZegmjXJxuop3Sq8wfBd2 Vp9VAvEJvvBlQKExR2xNRDKV/0LpW+VffIuzlWT2ex3WwGpFVeVSL0ZNJsPbzMYX j0aqGo9B/mHfXtKSQ415kGxiaQctnu5FqjNgSc00byzOU0YTiLsPwPdUgIt+nuQd WFSePoZsDYstkkJ8YaCA/LVzmZo0tNR8m+z7xmhCszUbMIV+iRSycUexEbCXoPx/ Ebg6ycyYMwguK7rL2dkjNWTkr3hP5CgLD7VnzVBYGiBY7ha0zOgbaYWl/33Az5Fb 0eaIyJRFCDmI32NZfri1WLc06K1gFcVcR6VO+BUqRHG6bkYnF/4xlla8ERhYgNeC Y9cs4Y9TNRges79k7jovpu9B5nicTEqMRQBubcARX5+w9zLg8h2aKH6inuVy1srn M9H/mjdCHMkySpSSrENw9Jk5I7RAgHHRgA1OTkB6Da02aMzPEh6fYHWeR7IpvxPc 2A/hxnZy0tTeZ4aKbds1GYZWUVDd3I8DlSVcT5Bq1g5kk6I+PN8= =jfay -----END PGP SIGNATURE-----