Debian: DSA 536-1 Critical: Libpng Buffer Overflows and Remote Exploits

Chris Evans discovered several vulnerabilities in libpng:

CAN-2004-0597 - Multiple buffer overflows exist, including when
handling transparency chunk data, which could be exploited to cause
arbitrary code to be executed when a specially crafted PNG image is
processed

CAN-2004-0598 - Multiple NULL pointer dereferences in
png_handle_iCPP() and elsewhere could be exploited to cause an
application to crash when a specially crafted PNG image is processed

CAN-2004-0599 - Multiple integer overflows in png_handle_sPLT(),
png_read_png() nctions and elsewhere could be exploited to cause an
application to crash, or potentially arbitrary code to be executed,
when a specially crafted PNG image is processed

In addition, a bug related to CAN-2002-1363 was fixed:

CAN-2004-0768 - A buffer overflow could be caused by incorrect
calculation of buffer offsets, possibly leading to the execution of
arbitrary code

For the current stable distribution (woody), these problems have been
fixed in libpng3 version 1...