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libpng invalid sCAL chunk processing vulnerability

Vulnerability Note VU#819894

Original Release Date: 2011-07-07 | Last Revised: 2011-07-07


libpng reads uninitialized memory when processing invalid sCAL chunks.


When libpng encounters a sCAL chunk that is empty it will read uninitialized memory. libpng also does not properly handle a sCAL chunk that lacks the terminating zero between the two strings conveyed.

Additional details can be found on the png-mng-implement mailing list archives.


By tricking a user into opening a specifically crafted PNG file within an application that uses libpng, an attacker may be able to cause a denial of service crash.


Apply an Update
This vulnerability is addressed in the following libpng versions: libpng-1.5.4, libpng-1.4.8, libpng-1.2.45, and libpng-1.0.55

Vendor Information

Affected   Unknown   Unaffected


Notified:  July 07, 2011 Updated:  July 07, 2011



Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Vendor Information

We are not aware of further vendor information regarding this vulnerability.

CVSS Metrics

Group Score Vector
Base N/A N/A
Temporal N/A N/A
Environmental N/A



Thanks to Glenn Randers-Pehrson for reporting this vulnerability.

This document was written by Jared Allar.

Other Information

CVE IDs: None
Severity Metric: 0.65
Date Public: 2011-07-07
Date First Published: 2011-07-07
Date Last Updated: 2011-07-07 18:39 UTC
Document Revision: 10

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