optiPNG
is a PNG optimizer that recompresses image files to a smaller size,
without losing any information. This program also converts external
formats (BMP, GIF, PNM and TIFF) to optimized PNG, and performs PNG
integrity checks and corrections.
If you wish to learn how PNG optimization works, or to know about
other similar tools, see the PNG Tech article
A guide to PNG optimization
.
SECURITY INFORMATION
You are strongly encouraged to upgrade to the latest version.
Here is a list of security-sensitive issues that affect the previous versions:
-
Zeng Yunxiang reported a global buffer overflow vulnerability in
the GIF decoder, and Thomas Hurst implemented a fix.
All versions prior to 0.7.8 that support
GIF files (i.e. from version 0.5
to version 0.7.7) are affected.
-
Joonun Jang reported a buffer overflow vulnerability in the GIF decoder,
discovered by a fuzzer developed by the SoftSec group at KAIST.
All versions prior to 0.7.7 that support
GIF files (i.e. from version 0.5
to version 0.7.6) are affected.
-
Jaeseung Choi reported an integer overflow vulnerability in the TIFF decoder.
All versions prior to 0.7.7 that support
TIFF files (i.e. from version 0.5.3
to version 0.7.6) are affected.
-
Henri Salo and Hans Jerry Illikainen reported two vulnerabilities in the
compressed BMP decoder, discovered by using the
American Fuzzy Lop.
All versions prior to 0.7.6 that support
compressed BMP files (i.e. from version 0.6
to version 0.7.5) are affected.
-
Gynvael Coldwind and Mateusz Jurczyk reported a use-after-free vulnerability
in the palette reduction code, affecting the versions
0.7,
0.7.1 and
0.7.2,
partially fixed in version
0.7.3,
and fully fixed in version
0.7.4.
