http://rt.openssl.org/Ticket/Display.html?id=1931&user=guest&pass=guest Index: openssl/ssl/d1_both.c =================================================================== --- d1_both.c.orig +++ d1_both.c @@ -561,7 +561,16 @@ dtls1_process_out_of_seq_message(SSL *s, if ((msg_hdr->frag_off+frag_len) > msg_hdr->msg_len) goto err; - if (msg_hdr->seq <= s->d1->handshake_read_seq) + /* Try to find item in queue, to prevent duplicate entries */ + pq_64bit_init(&seq64); + pq_64bit_assign_word(&seq64, msg_hdr->seq); + item = pqueue_find(s->d1->buffered_messages, seq64); + pq_64bit_free(&seq64); + + /* Discard the message if sequence number was already there, is + * too far in the future or the fragment is already in the queue */ + if (msg_hdr->seq <= s->d1->handshake_read_seq || + msg_hdr->seq > s->d1->handshake_read_seq + 10 || item != NULL) { unsigned char devnull [256];