CVE-2026-4985: dloebl CGIF整数溢出漏洞

#include <stdio.h> #include <stdint.h> // Conceptual PoC for Integer Overflow in cgif_addframe // This demonstrates how passing large values for width/height could cause an overflow. void cgif_addframe_vulnerable(int width, int height) { // Vulnerable calculation: size = width * height * channels // If width and height are large enough (e.g., 65536), the result overflows a 32-bit integer. int channels = 4; uint32_t size = (uint32_t)width * (uint32_t)height * channels; printf("Attempted allocation for %dx%d: %u bytes\n", width, height, size); // If overflow occurs, size becomes small, but subsequent writes use large indices. char* buffer = (char*)malloc(size); if (buffer == NULL) return; // Simulate writing data that would overflow the buffer for (int i = 0; i < width * height; i++) { if (i < size) { buffer[i] = 0; } else { // Out of bounds write printf("Overflow at index %d\n", i); } } free(buffer); } int main() { // Triggering values that cause width * height * 4 to wrap around // 65536 * 65536 * 4 = 17179869184, which overflows 32-bit int printf("Testing CVE-2026-4985 Integer Overflow:\n"); cgif_addframe_vulnerable(65536, 65536); return 0; }