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)
160 lines
6.5 KiB
Text
160 lines
6.5 KiB
Text
-----BEGIN PGP SIGNED MESSAGE-----
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Hash: SHA1
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=============================================================================
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FreeBSD-SA-03:06.openssl Security Advisory
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The FreeBSD Project
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Topic: OpenSSL timing-based SSL/TLS attack
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Category: crypto
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Module: openssl
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Announced: 2003-03-21
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Credits: Vlastimil Klima, Ondrej Pokorny, and Tomas Rosa
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Affects: All FreeBSD versions prior to 4.6-RELEASE-p12,
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4.7-RELEASE-p9, 5.0-RELEASE-p6
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Corrected: 2003-03-20 21:07:20 UTC (RELENG_4)
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2003-03-21 16:12:34 UTC (RELENG_4_7)
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2003-03-21 16:12:03 UTC (RELENG_4_6)
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2003-03-21 16:13:06 UTC (RELENG_5_0)
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FreeBSD only: NO
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I. Background
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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, commercial-
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grade, full-featured, and Open Source toolkit implementing the Secure
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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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This advisory addresses two separate flaws recently fixed in OpenSSL:
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(1) an RSA timing attack, and (2) the Klima-Pokorny-Rosa attack.
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- - - From the OpenSSL Project advisories (see references):
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(1) Researchers have discovered a timing attack on RSA keys, to which
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OpenSSL is generally vulnerable, unless RSA blinding has been
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turned on.
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(2) Czech cryptologists Vlastimil Klima, Ondrej Pokorny, and Tomas Rosa
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have come up with an extension of the "Bleichenbacher attack" on
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RSA with PKCS #1 v1.5 padding as used in SSL 3.0 and TLS 1.0.
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Their attack requires the attacker to open millions of SSL/TLS
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connections to the server under attack; the server's behaviour
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when faced with specially made-up RSA ciphertexts can reveal
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information that in effect allows the attacker to perform a single
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RSA private key operation on a ciphertext of its choice using the
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server's RSA key. Note that the server's RSA key is not
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compromised in this attack.
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III. Impact
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RSA timing attack:
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An RSA private key may be compromised.
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Klima-Pokorny-Rosa attack:
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A vulnerable server, when faced with specially made-up RSA
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ciphertexts, can reveal information that in effect allows the
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attacker to perform a single RSA private key operation on a
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ciphertext of its choice using the server's RSA key. Note that the
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server's RSA key is not compromised in this attack.
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IV. Workaround
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RSA timing attack:
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Disable the use of RSA or enable RSA blinding in OpenSSL using the
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RSA_blinding_on() function. The method of adjusting the list of
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acceptable ciphersuites varies from application to application. See
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the application's documentation for details.
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Klima-Pokorny-Rosa attack:
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Disable the use of ciphersuites which use PKCS #1 v1.5 padding in SSL
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or TLS. The method of adjusting the list of acceptable ciphersuites
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varies from application to application. See the application's
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documentation for details.
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V. Solution
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Perform one of the following:
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1) Upgrade your vulnerable system to 4-STABLE; or to the RELENG_4_7
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(4.7-RELEASE-p9), RELENG_4_6 (4.6-RELEASE-p12), or RELENG_5_0
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(5.0-RELEASE-p6) security branch 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 4.6, 4.7,
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and 5.0 systems which have already been patched for the issues resolved
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in FreeBSD-SA-03:02.openssl.
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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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# fetch ftp://ftp.FreeBSD.org/pub/FreeBSD/CERT/patches/SA-03:06/openssl.patch
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# fetch ftp://ftp.FreeBSD.org/pub/FreeBSD/CERT/patches/SA-03:06/openssl.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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c) Recompile the operating system as described in
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<URL: http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/makeworld.html >.
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Note that any statically linked applications that are not part of the
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base system (i.e. from the Ports Collection or other 3rd-party sources)
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must be recompiled.
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All affected applications must be restarted for them to use the
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corrected library. Though not required, rebooting may be the easiest
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way to accomplish this.
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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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Branch Revision
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Patch
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- -------------------------------------------------------------------------
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RELENG_4
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src/crypto/openssl/crypto/rsa/rsa_eay.c 1.2.4.6
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src/crypto/openssl/crypto/rsa/rsa_lib.c 1.2.2.7
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src/crypto/openssl/ssl/s3_srvr.c 1.1.1.1.2.7
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RELENG_4_6
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src/UPDATING 1.73.2.68.2.39
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src/crypto/openssl/crypto/rsa/rsa_eay.c 1.2.4.2.6.3
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src/crypto/openssl/crypto/rsa/rsa_lib.c 1.2.2.3.6.2
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src/crypto/openssl/ssl/s3_srvr.c 1.1.1.1.2.3.6.3
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src/sys/conf/newvers.sh 1.44.2.23.2.29
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RELENG_4_7
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src/UPDATING 1.73.2.74.2.11
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src/crypto/openssl/crypto/rsa/rsa_eay.c 1.2.4.3.2.2
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src/crypto/openssl/crypto/rsa/rsa_lib.c 1.2.2.4.2.1
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src/crypto/openssl/ssl/s3_srvr.c 1.1.1.1.2.5.2.1
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src/sys/conf/newvers.sh 1.44.2.26.2.11
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RELENG_5_0
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src/UPDATING 1.229.2.11
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src/crypto/openssl/crypto/rsa/rsa_eay.c 1.8.2.2
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src/crypto/openssl/crypto/rsa/rsa_lib.c 1.6.2.2
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src/crypto/openssl/ssl/s3_srvr.c 1.1.1.9.2.2
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src/sys/conf/newvers.sh 1.6.2.2
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- -------------------------------------------------------------------------
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VII. References
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<URL: http://cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2003-0131 >
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<URL: http://eprint.iacr.org/2003/052/ >
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<URL: http://www.openssl.org/news/secadv_20030317.txt >
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<URL: http://www.openssl.org/news/secadv_20030319.txt >
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Comment: FreeBSD: The Power To Serve
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-----END PGP SIGNATURE-----
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