Exposure of Sensitive Information to an Unauthorized Actor
Joomla! before 1.5.15 allows remote attackers to read an extension's XML file, and thereby obtain the extension's version number, via a direct request.
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.