An issue was discovered in CipherMail Community Gateway Virtual Appliances and Professional/Enterprise Gateway Virtual Appliances versions 1.0.1 through 4.7.1-0 and CipherMail Webmail Messenger Virtual Appliances 1.1.1 through 3.1.1-0. A Diffie-Hellman parameter of insufficient size could allow man-in-the-middle compromise of communications between CipherMail products and external SMTP clients.