CVE-2019-1891

A vulnerability in the web interface of Cisco Small Business 200, 300, and 500 Series Managed Switches could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to improper validation of requests sent to the web interface. An attacker could exploit this vulnerability by sending a malicious request to the web interface of an affected device. A successful exploit could allow the attacker to cause an unexpected reload of the device, resulting in a DoS condition.
Source: NIST
CVE-2019-1891