[stunnel-users] SSLv3 connections vulnerable in my environment?

Hello, I have a pretty standard stunnel server configuration with verify = 2 and clients, that don't speak TLS and can't easily be upgraded to support TLS. So disabling SSLv3 leads to handshake errors, I need to leave it enabled for now. The SSL connection is always renegotiated, a proprietary protocol is used inside SSL, and clients can be considered safe. Can the poodle security flaw realistically be used by a man in the middle to decrypt packets send over such an SSLv3 connection? If so, is there any other way to protect against the attack? Thank you.