From owner-freebsd-announce Tue Jan 23 13: 9: 5 2001 Delivered-To: freebsd-announce@freebsd.org Received: by hub.freebsd.org (Postfix, from userid 758) id 349E837B402; Tue, 23 Jan 2001 13:08:23 -0800 (PST) From: FreeBSD Security Advisories To: FreeBSD Security Advisories Subject: FreeBSD Security Advisory: FreeBSD-SA-01:08.ipfw Reply-To: security-advisories@freebsd.org Message-Id: <20010123210823.349E837B402@hub.freebsd.org> Date: Tue, 23 Jan 2001 13:08:23 -0800 (PST) Sender: owner-freebsd-announce@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org -----BEGIN PGP SIGNED MESSAGE----- ============================================================================= FreeBSD-SA-01:08 Security Advisory FreeBSD, Inc. Topic: ipfw/ip6fw allows bypassing of 'established' keyword Category: core Module: kernel Announced: 2001-01-23 Credits: Aragon Gouveia Affects: FreeBSD 3.x (all releases), FreeBSD 4.x (all releases), FreeBSD 3.5-STABLE and 4.2-STABLE prior to the correction date. Corrected: 2001-01-09 (FreeBSD 4.2-STABLE) 2001-01-12 (FreeBSD 3.5-STABLE) FreeBSD only: Yes I. Background ipfw is a system facility which allows IP packet filtering, redirecting, and traffic accounting. ip6fw is the corresponding utility for IPv6 networks, included in FreeBSD 4.0 and above. It is based on an old version of ipfw and does not contain as many features. II. Problem Description Due to overloading of the TCP reserved flags field, ipfw and ip6fw incorrectly treat all TCP packets with the ECE flag set as being part of an established TCP connection, which will therefore match a corresponding ipfw rule containing the 'established' qualifier, even if the packet is not part of an established connection. The ECE flag is not believed to be in common use on the Internet at present, but is part of an experimental extension to TCP for congestion notification. At least one other major operating system will emit TCP packets with the ECE flag set under certain operating conditions. Only systems which have enabled ipfw or ip6fw and use a ruleset containing TCP rules which make use of the 'established' qualifier, such as "allow tcp from any to any established", are vulnerable. The exact impact of the vulnerability on such systems is undetermined and depends on the exact ruleset in use. All released versions of FreeBSD prior to the correction date including FreeBSD 3.5.1 and FreeBSD 4.2 are vulnerable, but it was corrected prior to the (future) release of FreeBSD 4.3. III. Impact Remote attackers who construct TCP packets with the ECE flag set may bypass certain ipfw rules, allowing them to potentially circumvent the firewall. IV. Workaround Because the vulnerability only affects 'established' rules and ECE- flagged TCP packets, this vulnerability can be removed by adjusting the system's rulesets. In general, it is possible to express most 'established' rules in terms of a general TCP rule (with no TCP flag qualifications) and a 'setup' rule, but may require some restructuring and renumbering of the ruleset. V. Solution One of the following: 1) Upgrade the vulnerable FreeBSD system to FreeBSD 3.5-STABLE, or or 4.2-STABLE after the correction date. 2) Patch your present system by downloading the relevant patch from the below location: [FreeBSD 4.x] # fetch ftp://ftp.FreeBSD.org/pub/FreeBSD/CERT/patches/SA-01:08/ipfw-4.x.patch # fetch ftp://ftp.FreeBSD.org/pub/FreeBSD/CERT/patches/SA-01:08/ipfw-4.x.patch.asc [FreeBSD 3.x] # fetch ftp://ftp.FreeBSD.org/pub/FreeBSD/CERT/patches/SA-01:08/ipfw-3.x.patch # fetch ftp://ftp.FreeBSD.org/pub/FreeBSD/CERT/patches/SA-01:08/ipfw-3.x.patch.asc Verify the detached PGP signature using your PGP utility. Execute the following commands as root: # cd /usr/src # patch -p < /path/to/patch # cp /usr/src/sys/netinet/tcp.h /usr/src/sys/netinet/ip_fw.h /usr/include/netinet/ # cd /usr/src/sbin/ipfw # make depend && make all install # cd /usr/src/sys/modules/ipfw # make depend && make all install For 4.x systems, perform the following additional steps: # cp /usr/src/sys/netinet6/ip6_fw.h /usr/include/netinet6/ # cd /usr/src/sbin/ip6fw # make depend && make all install # cd /usr/src/sys/modules/ip6fw # make depend && make all install NOTE: The ip6fw patches have not yet been tested but are believed to be correct. The ip6fw software is not currently maintained and may be removed in a future release. If the system is using the ipfw or ip6fw kernel modules (see kldstat(8)), the module may be unloaded and the corrected module loaded into the kernel using kldload(8)/kldunload(8). This will require that the firewall rules be reloaded, usually be executing the /etc/rc.firewall script. Because the loading of the ipfw or ip6fw module will result in the system denying all packets by default, this should only be attempted when accessing the system via console or by careful use of a command such as: # kldload ipfw && sh /etc/rc.firewall which performs both operations sequentially. Otherwise, if the system has ipfw or ip6fw compiled into the kernel, the kernel will also have to be recompiled and installed, and the system will have to be rebooted for the changes to take effect. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.0.4 (FreeBSD) Comment: For info see http://www.gnupg.org iQCVAwUBOm3yulUuHi5z0oilAQEJbQP+Nf6JEKNUz0bOhgOYmY0DDCQNbY/2dlxA Qhs59HSB9Y7cwP+NuFKhix2fii8Y5oSOxjfMhllRl0yIQMHloG6orXNBuYJQ++d5 A/e+eoePNTzTo7kbaEZyvS3pGBodkueUmnKAqT9Ho/SGY00p4/JxpNcp3KuYT4Re gyKXSFV3rkQ= =7XOn -----END PGP SIGNATURE----- This is the moderated mailing list freebsd-announce. The list contains announcements of new FreeBSD capabilities, important events and project milestones. See also the FreeBSD Web pages at http://www.freebsd.org To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-announce" in the body of the message From owner-freebsd-announce Tue Jan 23 13:22:13 2001 Delivered-To: freebsd-announce@freebsd.org Received: by hub.freebsd.org (Postfix, from userid 758) id 18D8D37B69B; Tue, 23 Jan 2001 13:21:26 -0800 (PST) From: FreeBSD Security Advisories To: FreeBSD Security Advisories Subject: FreeBSD Security Advisory: FreeBSD-SA-01:09.crontab Reply-To: security-advisories@freebsd.org Message-Id: <20010123212126.18D8D37B69B@hub.freebsd.org> Date: Tue, 23 Jan 2001 13:21:26 -0800 (PST) Sender: owner-freebsd-announce@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org -----BEGIN PGP SIGNED MESSAGE----- ============================================================================= FreeBSD-SA-01:09 Security Advisory FreeBSD, Inc. Topic: crontab allows users to read certain files Category: core Module: crontab Announced: 2001-01-23 Credits: Kyong-won Cho Affects: FreeBSD 3.x (all releases), 4.x (all releases prior to 4.2) FreeBSD 3.5.1-STABLE and 4.1.1-STABLE prior to the correction date. Corrected: 2000-11-11 (FreeBSD 4.1.1-STABLE) 2000-11-20 (FreeBSD 3.5.1-STABLE) FreeBSD only: No I. Background crontab(8) is a program to edit crontab(5) files for use by the cron daemon, which schedules jobs to run at specified times. II. Problem Description crontab(8) was discovered to contain a vulnerability that may allow local users to read any file on the system that conform to a valid crontab(5) file syntax. Due to crontab(5) syntax requirements, the files that may be read is limited and subject to the following restrictions: * The file is a valid crontab(5) file, or: * The file is entirely commented out; every line contains either only whitespace, or begins with a '#' character. The greatest security vulnerability is the disclosure of crontab entries owned by other users, which may contain sensitive data such as keying material (although this would often be publically disclosed anyway at the time when the crontab job executes, via process arguments and environment, etc). All released versions of FreeBSD prior to the correction date including FreeBSD 4.1.1 are vulnerable to this problem. The problem was corrected prior to the release of FreeBSD 4.2. III. Impact Malicious local users can read arbitrary local files that conform to a valid crontab file syntax. IV. Workaround One of the following: 1) Utilize crontab allow/deny files (/var/cron/allow and /var/cron/deny) to limit access to use the crontab(8) utility. 2) Remove the setuid privileges from /usr/sbin/crontab. However, this will not allow users other than root to use cron. V. Solution One of the following: Upgrade the vulnerable FreeBSD system to 3.5-STABLE or 4.1.1-STABLE after the correction date. To patch your present system: download the relavent patch from the below location and execute the following commands as root: ftp://ftp.freebsd.org/pub/FreeBSD/CERT/patches/SA-01:09/crontab-4.x.patch ftp://ftp.freebsd.org/pub/FreeBSD/CERT/patches/SA-01:09/crontab-4.x.patch.asc Verify the detached PGP signature using your PGP utility. # cd /usr/src/usr.sbin/cron/crontab # patch -p < /path/to/patch # make depend && make all install -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.0.4 (FreeBSD) Comment: For info see http://www.gnupg.org iQCVAwUBOm32m1UuHi5z0oilAQGA+QQAhArbkzv/lo8QibLjyEFB3lta0IC5HSrJ hPuetiP/XViZNXntIAtm26M9QGRAhw0M1s9CU6PGD0zVJHtfh/nRoNxdU9vFLhJ6 xbJf6Wai6VTJpQK7dwXKIi6nplKlOSLhd6ZhvP1fe/6bDsbYywOxJdYGJZcyKtFA vG1n8lhzhog= =EJ7/ -----END PGP SIGNATURE----- This is the moderated mailing list freebsd-announce. The list contains announcements of new FreeBSD capabilities, important events and project milestones. See also the FreeBSD Web pages at http://www.freebsd.org To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-announce" in the body of the message From owner-freebsd-announce Thu Jan 25 13: 2:13 2001 Delivered-To: freebsd-announce@freebsd.org Received: from freefall.freebsd.org (freefall.FreeBSD.org [216.136.204.21]) by hub.freebsd.org (Postfix) with ESMTP id B8F8D37B69B; Thu, 25 Jan 2001 13:01:37 -0800 (PST) Received: (from kris@localhost) by freefall.freebsd.org (8.11.1/8.11.1) id f0PL1bs78217; Thu, 25 Jan 2001 13:01:37 -0800 (PST) (envelope-from security-advisories@FreeBSD.org) Date: Thu, 25 Jan 2001 13:01:37 -0800 (PST) Message-Id: <200101252101.f0PL1bs78217@freefall.freebsd.org> X-Authentication-Warning: freefall.freebsd.org: kris set sender to security-advisories@FreeBSD.org using -f From: FreeBSD Security Advisories To: FreeBSD Security Advisories Subject: FreeBSD Security Advisory: FreeBSD-SA-01:09.crontab [REVISED] Reply-To: security-advisories@FreeBSD.org Sender: owner-freebsd-announce@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org -----BEGIN PGP SIGNED MESSAGE----- ============================================================================= FreeBSD-SA-01:09 Security Advisory FreeBSD, Inc. Topic: crontab allows users to read certain files [REVISED] Category: core Module: crontab Announced: 2001-01-23 Revised: 2001-01-25 Credits: Kyong-won Cho Patch obtained from OpenBSD (Todd Miller ) Affects: FreeBSD 3.x (all releases), 4.x (all releases prior to 4.2) FreeBSD 3.5.1-STABLE and 4.1.1-STABLE prior to the correction date. Corrected: 2000-11-11 (FreeBSD 4.1.1-STABLE) 2000-11-20 (FreeBSD 3.5.1-STABLE) FreeBSD only: No 0. Revision History v1.0 2001-01-23 Initial release v1.1 2001-01-25 Update to credit OpenBSD as source of patch I. Background crontab(8) is a program to edit crontab(5) files for use by the cron daemon, which schedules jobs to run at specified times. II. Problem Description crontab(8) was discovered to contain a vulnerability that may allow local users to read any file on the system that conform to a valid crontab(5) file syntax. Due to crontab(5) syntax requirements, the files that may be read is limited and subject to the following restrictions: * The file is a valid crontab(5) file, or: * The file is entirely commented out; every line contains either only whitespace, or begins with a '#' character. The greatest security vulnerability is the disclosure of crontab entries owned by other users, which may contain sensitive data such as keying material (although this would often be publically disclosed anyway at the time when the crontab job executes, via process arguments and environment, etc). All released versions of FreeBSD prior to the correction date including FreeBSD 4.1.1 are vulnerable to this problem. The problem was corrected prior to the release of FreeBSD 4.2. III. Impact Malicious local users can read arbitrary local files that conform to a valid crontab file syntax. IV. Workaround One of the following: 1) Utilize crontab allow/deny files (/var/cron/allow and /var/cron/deny) to limit access to use the crontab(8) utility. 2) Remove the setuid privileges from /usr/sbin/crontab. However, this will not allow users other than root to use cron. V. Solution One of the following: Upgrade the vulnerable FreeBSD system to 3.5-STABLE or 4.1.1-STABLE after the correction date. To patch your present system: download the relavent patch from the below location and execute the following commands as root: ftp://ftp.freebsd.org/pub/FreeBSD/CERT/patches/SA-01:09/crontab-4.x.patch ftp://ftp.freebsd.org/pub/FreeBSD/CERT/patches/SA-01:09/crontab-4.x.patch.asc Verify the detached PGP signature using your PGP utility. # cd /usr/src/usr.sbin/cron/crontab # patch -p < /path/to/patch # make depend && make all install -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.0.4 (FreeBSD) Comment: For info see http://www.gnupg.org iQCVAwUBOnCTnVUuHi5z0oilAQGinAP8DtcJTo/0t/ajgbhccOSGMm9DHCN+jsou Nw+3rH07ImrSgeIyINi8d2J+tPL2eakesXm2yKOniuS25PoJN/GuzMC9Qvfybkvg cmKz3f4Fbzu9auWUUx2c+7GZargpGPRjxuNt86RucYswWjTT96MLs0ORGo9hZbXr F0kM+1EZoTg= =ONjc -----END PGP SIGNATURE----- This is the moderated mailing list freebsd-announce. The list contains announcements of new FreeBSD capabilities, important events and project milestones. See also the FreeBSD Web pages at http://www.freebsd.org To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-announce" in the body of the message From owner-freebsd-announce Thu Jan 25 13:13:11 2001 Delivered-To: freebsd-announce@freebsd.org Received: from freefall.freebsd.org (freefall.FreeBSD.org [216.136.204.21]) by hub.freebsd.org (Postfix) with ESMTP id D9F3437B402; Thu, 25 Jan 2001 13:12:35 -0800 (PST) Received: (from kris@localhost) by freefall.freebsd.org (8.11.1/8.11.1) id f0PLCZD81235; Thu, 25 Jan 2001 13:12:35 -0800 (PST) (envelope-from kris) Date: Thu, 25 Jan 2001 13:12:35 -0800 From: FreeBSD Security Advisories To: freebsd-security@freebsd.org Subject: HEADS UP: Problem with advisory delivery Message-ID: <20010125131235.A81121@freefall.freebsd.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i Sender: owner-freebsd-announce@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org -----BEGIN PGP SIGNED MESSAGE----- Hi all, There is something apparently broken with majordomo which is causing it to reject two of the recent advisories from being sent to the FreeBSD lists. Security advisories SA-01:07 and SA-01:10 are released (and made it to bugtraq), but have not shown up on the lists yet, despite re-sending. They'll be sent out as soon as jmb or someone can sort out the problem, in the meantime you can obtain them here: ftp://ftp.freebsd.org/pub/FreeBSD/CERT/advisories/FreeBSD-SA-01:07.xfree86.asc ftp://ftp.freebsd.org/pub/FreeBSD/CERT/advisories/FreeBSD-SA-01:10.bind.asc Sorry for the inconvenience Kris -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.0.4 (FreeBSD) Comment: For info see http://www.gnupg.org iQCVAwUBOnCW71UuHi5z0oilAQFJlwP+Jc3CCnHwYBAhX5eXGBlXlqr5A15pQEWU G5xB3bPLLRIrAyRxBZaceIIKdxxZWaVQg2zzS4OWZtDtwJpePPeKtCUcHVCK39O5 IPO9zG1KdS+n0PwtlCM+vuSRSFfnKDARiKc16sxG3+MDmTgJFTkd7DAGstP80/Yf /VKZu6eAKfg= =ptHS -----END PGP SIGNATURE----- This is the moderated mailing list freebsd-announce. The list contains announcements of new FreeBSD capabilities, important events and project milestones. See also the FreeBSD Web pages at http://www.freebsd.org To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-announce" in the body of the message