Cisco Email Security Appliance Filter Bypass Vulnerability

A vulnerability in the content scanning engine of Cisco AsyncOS Software for Cisco Email Security Appliances (ESA) could allow an unauthenticated, remote attacker to bypass configured message or content filters on the device.

The vulnerability is due to incomplete input validation of email message attachments in different formats. An attacker could exploit this vulnerability by sending a crafted email message with an attachment to the ESA. An exploit could allow the attacker to bypass configured content or message filters configured on the ESA. This message filter bypass could allow email attachments that contain malware to pass through the targeted device.

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-20170118-esa[“https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170118-esa”]