advancecomp: integer overflow in png_compress in pngex.cc (CVE-2019-9210)

In AdvanceCOMP 2.1, png_compress in pngex.cc in advpng has an integer overflow upon encountering an invalid PNG size, which results in an attempted memcpy to write into a buffer that is too small. (There is also a heap-based buffer over-read.)

References:

• https://sourceforge.net/p/advancemame/bugs/277/
• https://nvd.nist.gov/vuln/detail/CVE-2019-9210

Patch:

https://github.com/amadvance/advancecomp/commit/7894a6e684ce68ddff9f4f4919ab8e3911ac8040

Affected branches:

• master (82bc7fb6)