lunasvg Segmentation Fault Vulnerability in gray_find_cell Component

A segmentation fault vulnerability has been identified in lunasvg version 3.0.1. The issue arises in the gray_find_cell function within the plutovg-ft-raster.c file, leading to a segmentation violation when rendering SVGs with AddressSanitizer enabled. This vulnerability can be reproduced using the svg2png example included with the lunasvg distribution.

Impact

Exploitation of this vulnerability causes a segmentation fault, leading to a denial of service condition by crashing the application.

Reproduction

The vulnerability can be reproduced by compiling lunasvg with Clang 16.0.6, using CMake with AddressSanitizer enabled. After building the application, the svg2png example can be run with a crafted SVG file that triggers the segmentation fault. The AddressSanitizer log will indicate the memory access violation, confirming the exploitation of the vulnerability.