Exposure of Sensitive Information to an Unauthorized Actor
The penny-flooding protection mechanism in the CTxMemPool::accept method in bitcoind and Bitcoin-Qt before 0.4.9rc1, 0.5.x before 0.5.8rc1, 0.6.0 before 0.6.0.11rc1, 0.6.1 through 0.6.5 before 0.6.5rc1, and 0.7.x before 0.7.3rc1 allows remote attackers to determine associations between wallet addresses and IP addresses via a series of large Bitcoin transactions with insufficient fees.
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.