A vulnerability in the TCP/IP stack of Cisco Email Security Appliance (ESA), Cisco Web Security Appliance (WSA), and Cisco Secure Email and Web Manager, formerly Security Management Appliance, could allow an unauthenticated, remote attacker to crash the Simple Network Management Protocol (SNMP) service, resulting in a denial of service (DoS) condition. This vulnerability is due to an open port listener on TCP port 199. An attacker could exploit this vulnerability by connecting to TCP port 199. A successful exploit could allow the attacker to crash the SNMP service, resulting in a DoS condition. Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability. This advisory is available at the following link:https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ESA-SNMP-JLAJksWK Attention: Simplifying the Cisco portfolio includes the renaming of security products under one brand: Cisco Secure. For more information, see Meet Cisco Secure.