The png_format_buffer function in pngerror.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 allows remote attackers to cause a denial of service (application crash) via a crafted PNG image that triggers an out-of-bounds read during the copying of error-message data. NOTE: this vulnerability exists because of a CVE-2004-0421 regression. NOTE: this is called an off-by-one error by some sources.

pngrtran.c in libpng 1.5.x before 1.5.1 allows remote attackers to cause a denial of service (application crash) or possibly execute arbitrary code via a crafted palette-based PNG image that triggers a buffer overflow, related to the png_do_expand_palette function, the png_do_rgb_to_gray function, and an integer underflow. NOTE: some of these details are obtained from third party information.

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.

The png_decompress_chunk function in pngrutil.c in libpng 1.0.x before 1.0.53, 1.2.x before 1.2.43, and 1.4.x before 1.4.1 does not properly handle compressed ancillary-chunk data that has a disproportionately large uncompressed representation, which allows remote attackers to cause a denial of service (memory and CPU consumption, and application hang) via a crafted PNG file, as demonstrated by use of the deflate compression method on data composed of many occurrences of the same character, related to a "decompression bomb" attack.

libpng before 1.2.37 does not properly parse 1-bit interlaced images with width values that are not divisible by 8, which causes libpng to include uninitialized bits in certain rows of a PNG file and might allow remote attackers to read portions of sensitive memory via "out-of-bounds pixels" in the file.

The PNG reference library (aka libpng) before 1.0.43, and 1.2.x before 1.2.35, as used in pngcrush and other applications, allows context-dependent attackers to cause a denial of service (application crash) or possibly execute arbitrary code via a crafted PNG file that triggers a free of an uninitialized pointer in (1) the png_read_png function, (2) pCAL chunk handling, or (3) setup of 16-bit gamma tables.

Memory leak in the png_handle_tEXt function in pngrutil.c in libpng before 1.2.33 rc02 and 1.4.0 beta36 allows context-dependent attackers to cause a denial of service (memory exhaustion) via a crafted PNG file.

The png_check_keyword function in pngwutil.c in libpng before 1.0.42, and 1.2.x before 1.2.34, might allow context-dependent attackers to set the value of an arbitrary memory location to zero via vectors involving creation of crafted PNG files with keywords, related to an implicit cast of the '\0' character constant to a NULL pointer. NOTE: some sources incorrectly report this as a double free vulnerability.

Multiple off-by-one errors in libpng before 1.2.32beta01, and 1.4 before 1.4.0beta34, allow context-dependent attackers to cause a denial of service (crash) or have unspecified other impact via a PNG image with crafted zTXt chunks, related to (1) the png_push_read_zTXt function in pngread.c, and possibly related to (2) pngtest.c.