Cisco has released software updates that address the vulnerability described in this advisory. Customers may only install and expect support for software versions and feature sets for which they have purchased a license. By installing, downloading, accessing, or otherwise using such software upgrades, customers agree to follow the terms of the Cisco software license: https://www.cisco.com/c/en/us/products/end-user-license-agreement.html
At the time of publication, Cisco ESA and Cisco CES software releases 12.5.1-037 and later and 13.0.0-375 and later contained the fix for this vulnerability.
Cisco Cloud Email Security (CES) includes the Cisco ESA and Cisco Content Security Management Appliance (SMA) as part of the service solution. Cisco provides regular maintenance of the products included in this solution. Customers can also request a software upgrade by contacting Cisco CES support.