The png_handle_sCAL function in pngrutil.c in libpng 1.0.x before 1.0.55, 1.2.x before 1.2.45, 1.4.x before 1.4.8, and 1.5.x before 1.5.4 does not properly handle invalid sCAL chunks, which allows remote attackers to cause a denial of service (memory corruption and application crash) or possibly have unspecified other impact via a crafted PNG image that triggers the reading of uninitialized memory.
Buffer overflow in pngpread.c in libpng before 1.2.44 and 1.4.x before 1.4.3, as used in progressive applications, might allow remote attackers to execute arbitrary code via a PNG image that triggers an additional data row.
Memory leak in pngrutil.c in libpng before 1.2.44, and 1.4.x before 1.4.3, allows remote attackers to cause a denial of service (memory consumption and application crash) via a PNG image containing malformed Physical Scale (aka sCAL) chunks.