Exposure of Sensitive Information to an Unauthorized Actor
Apple Mail.app 3.5 on Mac OS X, when "Store draft messages on the server" is enabled, stores draft copies of S/MIME email in plaintext on the email server, which allows server owners and remote man-in-the-middle attackers to read sensitive mail.
CWE-200 - Information Exposure
An information exposure vulnerability is categorized as an information flow (IF) weakness, which can potentially allow unauthorized access to otherwise classified information in the application, such as confidential personal information (demographics, financials, health records, etc.), business secrets, and the application's internal environment.