The vulnerability, CVE-2019-1663, has a CVSS score of 9.8, allows unauthenticated, remote attackers to execute arbitrary code. Affected small business routers are used for wireless connectivity in small offices and home offices. The glitch stems from the interface, which does not properly double check the user-supplied data sent to it. The vulnerability was discovered by security researchers Yu Zhang and Haoliang Lu, and T. Shiomitsu of Pen Test Partners.
Source: https://threatpost.com/cisco-fixes-critical-flaw-in-wireless-vpn-firewall-routers/142284/