Apple QuickTime is installed on the remote Windows host.
Apple no longer supports any version of QuickTime on Windows. Lack of support implies that no new security patches for the product will be released by the vendor. As a result, it is likely to contain security vulnerabilities. Note that the last version of QuickTime released for Windows had known vulnerabilities related to processing atom indexes. A remote attacker can exploit these, by convincing a user to view a malicious website or open a crafted file, to cause heap corruption within QuickTime, resulting in the execution of arbitrary code in the context of the user or process running QuickTime.