Cisco has patched two serious vulnerabilities one critical and one high-severity in its email security appliance tool. Both bugs ultimately lead to a denial of service (DoS) on impacted devices and can be exploited by an attacker who simply sends an email. The company said it is not aware of any malicious use of either bug. The latest version of Cisco s AsyncOS Software for its Email Security Appliance is currently Version 12 however, this latest version is not impacted.
Source: https://threatpost.com/cisco-critical-vulnerability-patch/140726/