Exposure of Sensitive Information to an Unauthorized Actor
Cisco WebEx Training Center allows remote attackers to discover session numbers, and bypass host approval for audio-conference attendance, by reading HTML source code, aka Bug ID CSCul57126.
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.