Australia's Leading Computer Emergency Response Team

AA-2009.0139 -- [Win][UNIX/Linux] -- libpng: Reduced Security
Date: 15 June 2009
Original URL: http://www.auscert.org.au/render.html?cid=37&it=11111
References: ESB-2009.1425  ESB-2010.0282  ESB-2010.0338.2  

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AA-2009.0139                  AUSCERT Advisory

                             [Win][UNIX/Linux]
                         libpng: Reduced Security
                               15 June 2009
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        AusCERT Advisory Summary
        ------------------------

Product:              libpng
Operating System:     UNIX variants (UNIX, Linux, OSX)
                      Windows
Impact:               Reduced Security
Access:               Remote/Unauthenticated
CVE Names:            CVE-2009-2042
Member content until: Tuesday, July 07 2009

Revision History:     June 15 2009: Added CVE
                      June  9 2009: Initial Release

OVERVIEW:

       A security vulnerability has been confirmed in libpng.


IMPACT:

       The vendor has provided the following information regarding this
       vulnerability:

       "Jeff Phillips reported that several versions of libpng through 
       1.2.35 contain an uninitialized-memory-read bug that may have 
       security implications. Specifically, 1-bit (2-color) interlaced 
       images whose widths are not divisible by 8 may result in several 
       uninitialized bits at the end of certain rows in certain interlace 
       passes being returned to the user. An application that failed to 
       mask these out-of-bounds pixels might display or process them, 
       albeit presumably with benign results in most cases. This bug may be 
       fixed in version 1.2.36, released 7 May 2009, but the correct fix is 
       in version 1.2.37, released 4 June 2009." [1]


MITIGATION:

       The vendor has released libpng version 1.2.37 which is available for
       download from the vendor's website. [1]


REFERENCES:

       [1] libpng
           http://www.libpng.org/pub/png/libpng.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.
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