Exposure of Sensitive Information to an Unauthorized Actor
Mail in Apple Mac OS X before 10.9, when Kerberos authentication is enabled and TLS is disabled, sends invalid cleartext data, which allows remote attackers to obtain sensitive information by sniffing the network.
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.