BigBlueButton contains Response leaks in anonymous polls

BigBlueButton is an open source web conferencing system. This vulnerability only affects release candidates of BigBlueButton 2.4. The attacker can start a subscription for poll results before starting an anonymous poll, and use this subscription to see individual responses in the anonymous poll. The attacker had to be a meeting presenter. This issue is patched in version 2.4.0. There are no workarounds.