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AUSCERT Security Bulletin
ASB-2010.0072.2
Security Advisory for libpng-1.4.0 and earlier, 27 February 2010
24 March 2010
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AusCERT Security Bulletin Summary
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Product: libpng
Operating System: UNIX variants (UNIX, Linux, OSX)
Windows
Impact/Access: Denial of Service -- Remote with User Interaction
Resolution: Patch/Upgrade
CVE Names: CVE-2010-0205
Member content until: Saturday, April 3 2010
Comment: It is expected that vendors who package libpng will update their
packages shortly to reflect this fix.
Revision History: March 24 2010: Added CVE Reference
March 4 2010: Initial Release
OVERVIEW
The PNG Development Group has advised that libpng-1.4.0 and earlier are
vulnerable to a denial of service bug.
IMPACT
The PNG Development Group has made the following statement regarding
the vulnerability:
"Because of the efficient compression method used in Portable Network
Graphics (PNG) files, a small PNG file can expand tremendously,
acting as a "decompression bomb". Malformed PNG chunks can consume a
large amount of CPU and wall-clock time and large amounts of memory,
up to all memory available on a system.
Eventually libpng would discover that the chunk was malformed or
would run out of memory, abandon the chunk and return the allocated
memory, so this is only a nasty Denial of Service (DoS) vulnerability
that probably cannot be used to compromise a system." [1]
MITIGATION
The PNG Development Group has released libpng-1.4.1 which they state:
"... have been revised to use less CPU time and memory. Libpng-1.4.1
also provides functions that applications can use to further defend
against such files" [1]
REFERENCES
[1] Security Advisory for libpng-1.4.0 and earlier, 27 February 2010
http://libpng.sourceforge.net/ADVISORY-1.4.1.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
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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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