libvips is a fast image processing library with low memory needs. Prior to version 8.18.3, applications that define unusual custom libvips sources and use them to process untrusted uncompressed PPM i…

Summary

libvips is a fast image processing library with low memory needs. Prior to version 8.18.3, applications that define unusual custom libvips sources and use them to process untrusted uncompressed PPM images can trigger a max/min error in vips_source_read_to_memory in libvips/iofuncs/source.c. The function uses VIPS_MAX instead of VIPS_MIN when selecting the remaining read size, allowing up to 4032 bytes to be written beyond the allocated heap buffer and causing memory corruption or a process cras…