An inherent weakness in the CISCO ASA failover testing algorithm and methodology was identified and noted to CISCO TAC and PSIRT. In general, the two weaknesses have been identified as a race condition between two different failover testing processes and a lack of authentication for failover messages between active and standby.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/41539/ciscoASA.txt
Source: https://packetstormsecurity.com/files/41539/ciscoASA.txt.html