CVE-2026-33984 FreeRDP堆缓冲区溢出漏洞

/* * PoC Concept for CVE-2026-33984 * Demonstrating the logic flaw in resize_vbar_entry */ #include <stdio.h> #include <stdlib.h> #include <string.h> typedef struct { size_t size; size_t count; char *pixels; } BarEntry; // Simulating the vulnerable logic void vulnerable_resize(BarEntry *entry, size_t new_count) { if (new_count > entry->size) { // VULNERABILITY: size updated before reallocation entry->size = new_count; // Simulate allocation failure char *new_pixels = (char *)realloc(entry->pixels, new_count); if (!new_pixels) { printf("Reallocation failed, but size is already updated!\n"); return; // Returns with inflated size and old pointer } entry->pixels = new_pixels; } } int main() { BarEntry entry = {0}; entry.pixels = (char *)malloc(10); entry.size = 10; printf("Initial size: %zu\n", entry.size); // Trigger the vulnerable path with a request that forces a realloc failure scenario // In a real exploit, this would be triggered by specific RDP stream data vulnerable_resize(&entry, 1000); printf("Size after failed realloc: %zu\n", entry.size); printf("Buffer pointer: %p\n", (void*)entry.pixels); // Next call skips realloc because 500 <= 1000 (inflated size) vulnerable_resize(&entry, 500); // Overflow happens here writing 500 bytes to a 10-byte buffer memset(entry.pixels, 'A', 500); return 0; }