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OpenSSL PRNG weakness (up to 0.9.6a)
2001-013
Published: 2001-08-23 00:00:00
Updated: 2001-08-23 00:00:00

                 NetBSD Security Advisory 2001-013
                 =================================

Topic:          OpenSSL PRNG weakness (up to 0.9.6a)

Version:        NetBSD-current: source prior to July 10, 2001
                NetBSD 1.5.1:   affected
                NetBSD 1.5:     affected
                pkgsrc:         openssl packages prior to 0.9.6b or 0.9.6nb1

Severity:       attacker can predict sequence of future PRNG outputs

Fixed:          NetBSD-current:         July 10, 2001
                NetBSD-1.5 branch:      July 29, 2001 (1.5.2 includes the fix)
                pkgsrc:                 openssl-0.9.6b or openssl-0.9.6nb1

Abstract
========

The OpenSSL libcrypto includes a PRNG (pseudo random number generator)
implementation.  The logic used for PRNG was not strong enough,
and allows attackers to guess the internal state of the PRNG.
Therefore, attackers can predict future PRNG output.


Technical Details
=================

http://www.openssl.org/news/secadv_prng.txt


Solutions and Workarounds
=========================

The problem can be remedied by replacing the libcrypto library,
and recompiling all statically-linked binaries on the system that
use this library.

The following instructions describe how to upgrade your openssl
libraries by updating your source tree and rebuilding and installing
a new version of telnetd(8).


* All NetBSD releases using openssl from pkgsrc:

        If you are using openssl from pkgsrc, upgrade it to either of
        the following packages:
                openssl-0.9.6b or higher
                openssl-0.9.6nb1 (0.9.6 + specific fix for the issue)

        Also, make sure that you upgrade any statically-linked binaries
        in packages and local applications that have been linked with
        libcrypto.


* NetBSD-current:

        Systems running NetBSD-current dated from before 2001-07-10
        should be upgraded to NetBSD-current dated 2001-07-11 or later.

        The following directories need to be updated from the
        netbsd-current CVS branch (aka HEAD):
                src/crypto/dist/openssl
                src/lib/libcrypto

        To update from CVS, re-build, and re-install the openssl
        libraries:
                # cd src
                # cvs update -d -P crypto/dist/openssl lib/libcrypto
                # cd lib/libcrypto
                # make cleandir dependall
                # make install

        You also need to upgrade any statically-linked binaries
        that use libcrypto.  Whilst there are no statically-linked
        binaries in the default NetBSD installation that use
        libcrypto, it would be a good idea to run a full build
        (i.e. "make build").


* NetBSD 1.5, 1.5.1:

        Systems running NetBSD 1.5 or 1.5.1 sources dated from
        before 2001-07-29 should be upgraded from NetBSD 1.5.x
        sources dated 2001-07-30 or later.

        NetBSD 1.5.2 is not vulnerable.

        The following source needs to be updated to version 1.2
        or later from the netbsd-1-5 CVS branch:
                crypto/dist/openssl/crypto/rand/md_rand.c

        To update from CVS, re-build, and re-install the openssl
        libraries:
                # cd src
                # cvs update -d -P crypto/dist/openssl/crypto/rand
                # cd lib/libcrypto
                # make cleandir dependall
                # make install


        Alternatively, apply the following patch (with potential offset
        differences):
                ftp://ftp.netbsd.org/pub/NetBSD/security/patches/SA2001-013-openssl-1.5.patch

        To patch, re-build and re-install the openssl libraries:
                # cd src/crypto/dist/openssl/crypto/rand
                # patch < /path/to/SA2001-013-openssl-1.5.patch
                # cd ../../../../../lib/libcrypto
                # make cleandir dependall
                # make install


        You also need to upgrade any statically-linked binaries
        that use libcrypto.  Whilst there are no statically-linked
        binaries in the default NetBSD installation that use
        libcrypto, it would be a good idea to run a full build
        (i.e. "make build").


Thanks To
=========

Jun-ichiro Hagino for the fix to -current and 1.5

Markku-Juhani O. Saarinen for discovering the problem
in the PRNG and reporting it to the OpenSSL project.


Revision History
================

        2001-08-23      Initial release


More Information
================

An up-to-date PGP signed copy of this release will be maintained at
  ftp://ftp.netbsd.org/pub/NetBSD/security/advisories/NetBSD-SA2001-013.txt.asc

Information about NetBSD and NetBSD security can be found at
http://www.NetBSD.ORG/ and http://www.NetBSD.ORG/Security/.


Copyright 2001, The NetBSD Foundation, Inc.  All Rights Reserved.

$NetBSD: NetBSD-SA2001-013.txt,v 1.13 2001/08/23 02:03:23 lukem Exp $







 

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