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EnGarde Secure Linux Security Advisory: OpenSSL PRNG Weakness

Jul 11, 2001, 01:49 (0 Talkback[s])
Date: Tue, 10 Jul 2001 13:55:59 -0400 (EDT)
From: EnGarde Secure Linux <security@guardiandigital.com>
Subject: [ESA-20010709-01] OpenSSL PRNG Weakness

+------------------------------------------------------------------------+
| EnGarde Secure Linux Security Advisory                   July 09, 2001 |
| http://www.engardelinux.org/                           ESA-20010709-01 |
|                                                                        |
| Package:  openssl                                                      |
| Summary:  There is a design weakness in OpenSSL's PRNG.                |
+------------------------------------------------------------------------+

  EnGarde Secure Linux is a secure distribution of Linux that features
  improved access control, host and network intrusion detection, Web
  based secure remote management, complete e-commerce using AllCommerce,
  and integrated open source security tools.


OVERVIEW
- --------
  A weakness exists in the pseudo-random number generator (PRNG) in all
  version of OpenSSL up to and including 0.9.6a.  Given knowledge of
  past results of PRNG queries an attacker can predict future results.


DETAIL
- ------
  There is a design error in OpenSSL's PRNG which can allow an attacker to
  determine the internal state of the PRNG.  Based on the output of
  several hundered 1-byte PRNG requests an attacker can reconstruct the
  PRNG's internal state and predict future PRNG output.

  The impact of this vulnerability is rather small, as the OpenSSL team
  has described:

    "It is unlikely for applications to request PRNG bytes in a pattern
     allowing for the attack against the OpenSSL PRNG.  Typically,
     applications will request PRNG bytes in larger chunks.
     No applications is known to us which is actually vulnerable."

  In any event, we highly recommend that all users upgrade to the latest
  openssl packages as outlined in this advisory.


SOLUTION
- --------
  All users should upgrade to the most recent version, as outlined in
  this advisory.

  Guardian Digital recently made available the Guardian Digital Secure
  Update, a means to proactively keep systems secure and manage 
  system software. EnGarde users can automatically update their system
  using the Guardian Digital WebTool secure interface.

  If choosing to manually upgrade this package, updates can be
  obtained from:

    ftp://ftp.engardelinux.org/pub/engarde/stable/updates/
    http://ftp.engardelinux.org/pub/engarde/stable/updates/

  Before upgrading the package, the machine must either:

    a) be booted into a "standard" kernel; or
    b) have LIDS disabled.

  To disable LIDS, execute the command:

    # /sbin/lidsadm -S -- -LIDS_GLOBAL

  To install the updated package, execute the command:

    # rpm -Uvh <filename>

  To reload the LIDS configuration, execute the command:

    # /usr/sbin/config_lids.pl

  To re-enable LIDS (if it was disabled), execute the command:

    # /sbin/lidsadm -S -- +LIDS_GLOBAL

  To verify the signature of the updated packages, execute the command:

    # rpm -Kv <filename>


UPDATED PACKAGES
- ----------------
  These updated packages are for EnGarde Secure Linux 1.0.1 (Finestra).

  Source Packages:

    SRPMS/openssl-0.9.6-1.0.14.src.rpm
      MD5 Sum:  420d7e9d0687f313059a64935be6f550

  i386 Binary Packages:

    i386/openssl-0.9.6-1.0.14.i386.rpm
      MD5 Sum:  347000c0645194ab5feb83eb92d2355c

    i386/openssl-devel-0.9.6-1.0.14.i386.rpm
      MD5 Sum:  09125870402b05ad8ab75d74271893a3

    i386/openssl-misc-0.9.6-1.0.14.i386.rpm
      MD5 Sum:  e865af2f976115e92f99a6ce7fd1cb1b

  i386 Binary Packages:

    i686/openssl-0.9.6-1.0.14.i686.rpm
      MD5 Sum:  4d612208e3952bdb375ad36e614abf98

    i686/openssl-devel-0.9.6-1.0.14.i686.rpm
      MD5 Sum:  8a1b228357a1fe51a96aeb9afa3981f2

    i686/openssl-misc-0.9.6-1.0.14.i686.rpm
      MD5 Sum:  1e5eb36c5db32a79dbdfccb3899ae9dc


REFERENCES
- ----------

  Guardian Digital's public key:
    http://ftp.engardelinux.org/pub/engarde/ENGARDE-GPG-KEY

  Credit for the discovery of this bug goes to:
    Markku-Juhani O. Saarinen 

  OpenSSL's Official Web Site:
    http://www.openssl.org/


- --------------------------------------------------------------------------
$Id: ESA-20010709-01-openssl,v 1.2 2001/07/10 15:34:45 rwm Exp rwm $
- --------------------------------------------------------------------------
Author: Ryan W. Maple, <ryan@guardiandigital.com>>
Copyright 2001, Guardian Digital, Inc.