Cisco AsyncOS on Email Security Appliance (ESA) devices with software 8.5.6-073, 8.5.6-074, and 9.0.0-461, when clustering is enabled, allows remote attackers to cause a denial of service (clustering and SSH outage) via a packet flood, aka Bug IDs CSCur13704 and CSCuq05636.
The anti-spam scanner on Cisco Email Security Appliance (ESA) devices 3.3.1-09, 7.5.1-gpl-022, and 8.5.6-074 allows remote attackers to bypass intended e-mail restrictions via a malformed DNS SPF record, aka Bug IDs CSCuu35853 and CSCuu37733.