3571e53040
patches for easier mirroring, to eliminate a special copy, to make www.freebsd.org/security a full copy of security.freebsd.org and be eventually be the same. For now files are just sitting there. The symlinks are missing. Discussed on: www (repository location) Discussed with: simon (so)
155 lines
6 KiB
Text
155 lines
6 KiB
Text
-----BEGIN PGP SIGNED MESSAGE-----
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Hash: SHA1
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=============================================================================
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FreeBSD-SA-09:03.ntpd Security Advisory
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The FreeBSD Project
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Topic: ntpd cryptographic signature bypass
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Category: contrib
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Module: ntpd
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Announced: 2009-01-13
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Credits: Google Security Team
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Affects: All FreeBSD releases
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Corrected: 2009-01-13 21:19:27 UTC (RELENG_7, 7.1-STABLE)
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2009-01-13 21:19:27 UTC (RELENG_7_1, 7.1-RELEASE-p2)
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2009-01-13 21:19:27 UTC (RELENG_7_0, 7.0-RELEASE-p9)
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2009-01-13 21:19:27 UTC (RELENG_6, 6.4-STABLE)
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2009-01-13 21:19:27 UTC (RELENG_6_4, 6.4-RELEASE-p3)
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2009-01-13 21:19:27 UTC (RELENG_6_3, 6.3-RELEASE-p9)
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CVE Name: CVE-2009-0021
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For general information regarding FreeBSD Security Advisories,
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including descriptions of the fields above, security branches, and the
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following sections, please visit <URL:http://security.FreeBSD.org/>.
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I. Background
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The ntpd daemon is an implementation of the Network Time Protocol
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(NTP) used to synchronize the time of a computer system to a reference
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time source.
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FreeBSD includes software from the OpenSSL Project. The OpenSSL
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Project is a collaborative effort to develop a robust,
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commercial-grade, full-featured Open Source toolkit implementing the
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Secure Sockets Layer (SSL v2/v3) and Transport Layer Security (TLS v1)
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protocols as well as a full-strength general purpose cryptography
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library.
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II. Problem Description
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The EVP_VerifyFinal() function from OpenSSL is used to determine if a
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digital signature is valid. When ntpd(8) is set to cryptographically
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authenticate NTP data it incorrectly checks the return value from
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EVP_VerifyFinal().
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III. Impact
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An attacker which can send NTP packets to ntpd, which uses
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cryptographic authentication of NTP data, may be able to inject
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malicious time data causing the system clock to be set incorrectly.
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IV. Workaround
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Use IP based restrictions in ntpd itself or in IP firewalls to
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restrict which systems can send NTP packets to ntpd.
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NOTE WELL: If ntpd is not explicitly set to use cryptographic
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authentication of NTP data the setup is not vulnerable to the issue
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as described in this Security Advisory.
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V. Solution
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NOTE WELL: Due to an error in building the updates, this fix is not
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available via freebsd-update at the time of this advisory. We expect
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that this will be fixed within the next 48 hours.
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Perform one of the following:
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1) Upgrade your vulnerable system to 6-STABLE, or 7-STABLE, or to the
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RELENG_7_1, RELENG_7_0, RELENG_6_4, or RELENG_6_3 security branch
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dated after the correction date.
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2) To patch your present system:
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The following patches have been verified to apply to FreeBSD 6.3, 6.4,
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7.0, and 7.1 systems.
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a) Download the relevant patch from the location below, and verify the
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detached PGP signature using your PGP utility.
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[FreeBSD 6.4 and 7.1]
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# fetch http://security.FreeBSD.org/patches/SA-09:03/ntpd.patch
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# fetch http://security.FreeBSD.org/patches/SA-09:03/ntpd.patch.asc
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[FreeBSD 6.3 and 7.0]
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# fetch http://security.FreeBSD.org/patches/SA-09:03/ntpd63.patch
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# fetch http://security.FreeBSD.org/patches/SA-09:03/ntpd63.patch.asc
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b) Execute the following commands as root:
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# cd /usr/src
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# patch < /path/to/patch
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# cd /usr/src/usr.sbin/ntp/ntpd
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# make obj && make depend && make && make install
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# /etc/rc.d/ntpd restart
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VI. Correction details
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The following list contains the revision numbers of each file that was
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corrected in FreeBSD.
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CVS:
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Branch Revision
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Path
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- -------------------------------------------------------------------------
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RELENG_6
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src/contrib/ntp/ntpd/ntp_crypto.c 1.1.1.3.8.2
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RELENG_6_4
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src/UPDATING 1.416.2.40.2.6
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src/sys/conf/newvers.sh 1.69.2.18.2.9
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src/contrib/ntp/ntpd/ntp_crypto.c 1.1.1.3.8.1.2.1
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RELENG_6_3
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src/UPDATING 1.416.2.37.2.14
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src/sys/conf/newvers.sh 1.69.2.15.2.13
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src/contrib/ntp/ntpd/ntp_crypto.c 1.1.1.3.20.1
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RELENG_7
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src/contrib/ntp/ntpd/ntp_crypto.c 1.1.1.3.18.2
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RELENG_7_1
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src/UPDATING 1.507.2.13.2.5
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src/sys/conf/newvers.sh 1.72.2.9.2.6
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src/contrib/ntp/ntpd/ntp_crypto.c 1.1.1.3.18.1.2.1
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RELENG_7_0
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src/UPDATING 1.507.2.3.2.13
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src/sys/conf/newvers.sh 1.72.2.5.2.13
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src/contrib/ntp/ntpd/ntp_crypto.c 1.1.1.3.22.1
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- -------------------------------------------------------------------------
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Subversion:
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Branch/path Revision
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- -------------------------------------------------------------------------
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stable/6/ r187194
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releng/6.4/ r187194
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releng/6.3/ r187194
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stable/7/ r187194
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releng/7.1/ r187194
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releng/7.0/ r187194
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- -------------------------------------------------------------------------
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VII. References
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http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2009-0021
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http://security.FreeBSD.org/advisories/FreeBSD-SA-09:02.openssl.asc
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The latest revision of this advisory is available at
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http://security.FreeBSD.org/advisories/FreeBSD-SA-09:03.ntpd.asc
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