-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

===========================================================================
AA-2007.0116                  AUSCERT Advisory

                               [UNIX/Linux]
                     Mulitple vulnerabilities in rsync
                              5 December 2007
- ---------------------------------------------------------------------------

        AusCERT Advisory Summary
        ------------------------

Product:              rsync
Operating System:     UNIX variants (UNIX, Linux, OSX)
Impact:               Inappropriate Access
Access:               Remote/Unauthenticated
CVE Names:            CVE-2007-6200 CVE-2007-6199
Member content until: Monday, December 31 2007

Revision History:     December 5 2007: Added CVE References
                      December 3 2007: Initial Release

OVERVIEW:

       Multiple vulnerabilities have been reported in rsync, which allows
       remote users to bypass certain security restrictions.


IMPACT:

       The vendor has released the following information regarding these
       vulnerabilities:

       a) 'If you are running a writable rsync daemon with "use chroot = 
          no", there is at least one way for someone to trick rsync into 
          creating a symlink that points outside of the module's hierarchy.

          This means that if you are allowing access from users who you 
          don't trust, that you should either figure out a way to turn on 
          "use chroot", or configure the daemon to refuse the --links 
          option (see "refuse options" in the rsyncd.conf manpage) which 
          will disable the ability of the rsync module to receive symlinks. 
          After doing so, you should also check that any existing symlinks 
          in the daemon hierarchy are safe.' [1]

       b) 'If you are running a writable rsync daemon that is using one of 
          the "exclude", "exclude from", or "filter" options in the 
          rsyncd.conf file to hide data from your users, you should be aware 
          that there are tricks that a user can play with symlinks and/or 
          certain options that can allow a user that knows the name of a 
          hidden file to access it or overwrite it (if file permissions 
          allow that).' [1]


MITIGATION:

       A patch to rectify these vulnerabilities is available for download
       via the rsync website.[2]

       Rsync also recommends that 'Any admin applying that patch should 
       read the "munge symlinks" section of the modified rsyncd.conf 
       manpage for more information.' [1] 


REFERENCES:

       [1] Rsync Security Advisories
           http://samba.org/rsync/security.html

       [2] Rsync
           http://samba.org/rsync/download.html

AusCERT has made every effort to ensure that the information contained
in this document is accurate.  However, the decision to use the information
described is the responsibility of each user or organisation. The decision to
follow or act on information or advice contained in this security bulletin is
the responsibility of each user or organisation, and should be considered in
accordance with your organisation's site policies and procedures. AusCERT
takes no responsibility for consequences which may arise from following or
acting on information or advice contained in this security bulletin.

If you believe that your computer system has been compromised or attacked in 
any way, we encourage you to let us know by completing the secure National IT 
Incident Reporting Form at:

        http://www.auscert.org.au/render.html?it=3192

===========================================================================
Australian Computer Emergency Response Team
The University of Queensland
Brisbane
Qld 4072

Internet Email: auscert@auscert.org.au
Facsimile:      (07) 3365 7031
Telephone:      (07) 3365 4417 (International: +61 7 3365 4417)
                AusCERT personnel answer during Queensland business hours
                which are GMT+10:00 (AEST).
                On call after hours for member emergencies only.
===========================================================================

-----BEGIN PGP SIGNATURE-----
Comment: http://www.auscert.org.au/render.html?it=1967

iQCVAwUBR1Xl7Sh9+71yA2DNAQL5dAP/U3AsxQHJ1m44y3T6WNdp4H7I6I49Upms
I2g8WRF9K1XNQdL0uHeZJjzEKGskyrjgyoMx40uFWRTdu9m6uJLmaxx7UmY2URyI
YZ+GngcY/NnnxXSTH7JWUyFdxkYeWzcsfAheDzQQeuIS/ULtSI7TPu04sTjz0CiI
badK8SEPFX0=
=JerY
-----END PGP SIGNATURE-----