Cisco AsyncOS before 8.5.7-043 9.x before 9.1.1-023 and 9.5.x and 9.6.x before 9.6.0-046 on Email Security Appliance (ESA) devices mishandles malformed fields during body-contains attachment-contains every-attachment-contains attachment-binary-contains dictionary-match and attachment-dictionary-match filtering which allows remote attackers to cause a denial of service (memory consumption) via a crafted attachment in an e-mail message aka Bug ID CSCuv47151.