Exposure of Sensitive Information to an Unauthorized Actor
Spotlight in Apple OS X before 10.10.2 does not enforce the Mail "Load remote content in messages" configuration, which allows remote attackers to discover recipient IP addresses by including an inline image in an HTML e-mail message and logging HTTP requests for this image's URL.
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.