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     NetBSD Security Advisory 2002-002
     =================================

Topic:    gzip buffer overrun with long filename

Version:  NetBSD-current:  prior to January 16, 2002
    NetBSD-1.5.*:  affected up to and including 1.5.2
    NetBSD-1.4.*:  affected up to and including 1.4.3

Severity:  local buffer overrun
    (possible remote root privilege compromise if a system
    runs certain alternative ftp daemons)

Fixed:    NetBSD-current:    January 16, 2002
    NetBSD-1.5 branch:  January 16, 2002
    NetBSD-1.4 branch:  January 16, 2002


Abstract
========

/usr/bin/gzip, a file compression program, does not properly check
supplied filenames against its buffer size.  It could lead to
execution of arbitrary code under the privilege with which gzip is
running.

There are ftp daemon programs that invoke gzip on demand (like wu-ftpd).
If your systems run these daemons, depending on the configuration it could
lead to a remote root compromise.


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

http://www.securityfocus.com/bid/3712


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


The following instructions describe how to upgrade your /usr/bin/gzip
binaries by updating your source tree and rebuilding and
installing a new version of /usr/bin/gzip.

* NetBSD-current:

  Systems running NetBSD-current dated from before 2002-01-16
  should be upgraded to NetBSD-current dated 2001-01-17 or later.

  The following directories need to be updated from the
  netbsd-current CVS branch (aka HEAD):
    gnu/usr.bin/gzip

  To update from CVS, re-build, and re-install gzip:
    # cd src
    # cvs update -d -P gnu/usr.bin/gzip
    # cd gnu/usr.bin/gzip

    # make cleandir dependall
    # make install


* NetBSD 1.5, 1.5.1, 1.5.2:

  Systems running NetBSD 1.5, 1.5.1 or 1.5.2 sources dated from
  before 2002-01-16 should be upgraded from NetBSD 1.5.*
  sources dated 2002-01-17 or later.

  NetBSD 1.5.3 will not be vulnerable.

  The following directories need to be updated from the
  netbsd-1-5 CVS branch:
    gnu/usr.bin/gzip

  To update from CVS, re-build, and re-install gzip:

    # cd src
    # cvs update -d -P gnu/usr.bin/gzip
    # cd gnu/usr.bin/gzip

    # make cleandir dependall
    # make install

        Alternatively, apply the following patch (with potential offset
        differences):

                ftp://ftp.netbsd.org/pub/NetBSD/security/patches/SA2002-002-gzip.patch

        To patch, re-build and re-install gzip(1):

                # cd src/gnu/usr.bin/gzip
                # patch < /path/to/SA2002-002-gzip.patch

    # make cleandir dependall
    # make install


* NetBSD 1.4, 1.4.1, 1.4.2, 1.4.3:

  Systems running NetBSD 1.4, 1.4.1, 1.4.2 or 1.4.3 sources dated from
  before 2002-01-16 should be upgraded from NetBSD 1.4.*
  sources dated 2002-01-17 or later.

  The following directories need to be updated from the
  netbsd-1-4 CVS branch:
    gnu/usr.bin/gzip

  To update from CVS, re-build, and re-install gzip:

    # cd src
    # cvs update -d -P gnu/usr.bin/gzip
    # cd gnu/usr.bin/gzip

    # make cleandir dependall
    # make install

        Alternatively, apply the following patch (with potential offset
        differences):

                ftp://ftp.netbsd.org/pub/NetBSD/security/patches/SA2002-002-gzip.patch

        To patch, re-build and re-install gzip(1):

                # cd src/gnu/usr.bin/gzip
                # patch < /path/to/SA2002-002-gzip.patch

    # make cleandir dependall
    # make install


Thanks To
=========

Jun-ichiro itojun Hagino for patches, and preparing advisory text.


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

  2002-03-12  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-SA2002-002.txt.asc

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


Copyright 2002, The NetBSD Foundation, Inc.  All Rights Reserved.

$NetBSD: NetBSD-SA2002-002.txt,v 1.6 2002/03/12 05:45:35 groo Exp $

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