CVE-2026-5477 wolfSSL CMAC整数溢出漏洞

#include <stdio.h> #include <stdint.h> // Simulation of the vulnerable logic in wc_CmacUpdate void simulate_vulnerable_update(uint32_t totalSz, int isLastBlock) { // The vulnerable guard: checks if totalSz is not zero // In the real code, totalSz wraps around after 4GB of data if (totalSz != 0) { printf("[+] Performing XOR chaining with previous state.\n"); } else { // This block is executed when totalSz wraps to 0 after 4GB printf("[!] VULNERABLE: Skipping XOR (treated as first block).\n"); printf("[!] CBC-MAC chain state is discarded/reset.\n"); } } int main() { // Scenario: Processing data that causes totalSz to wrap // 2^28 blocks * 16 bytes/block = 4GB (approx limit for word32) printf("--- Normal Operation (< 4GB) ---\n"); simulate_vulnerable_update(16, 0); printf("\n--- After 4GB Overflow (totalSz wraps to 0) ---\n"); // Simulate the state where totalSz has wrapped around to 0 // due to integer overflow after processing massive data. simulate_vulnerable_update(0, 0); printf("\n--- Impact ---\n"); printf("An attacker can now send a message with a common suffix,\n"); printf("and it will generate the same CMAC tag as the previous message.\n"); return 0; }