Thomson Reuters UltraTax CS 2017 on Windows in a client/server configuration transfers customer records and bank account numbers in cleartext over SMBv2 which allows attackers to (1) obtain sensitive information by sniffing the network or (2) conduct man-in-the-middle (MITM) attacks via unspecified vectors. The customer record transferred in cleartext contains: Client ID Full Name Spouse's Full Name Social Security Number Spouse's Social Security Number Occupation Spouse's Occupation Daytime Phone Home Phone Tax Preparer Federal and State Taxes to File Bank Name Bank Account Number and possibly other sensitive information.