Exposure of Sensitive Information to an Unauthorized Actor
Michael Salzer Guestbox 0.6, and other versions before 0.8, allows remote attackers to obtain the source IP addresses of guestbook entries via a direct request to /gb/gblog.
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.