Layer 2 network filtering capabilities such as IPv6 RA guard or ARP inspection can be bypassed using combinations of VLAN 0 headers and LLC/SNAP headers.
A vulnerability in the web-based management interface of Cisco Small Business 200 Series Smart Switches, Cisco Small Business 300 Series Managed Switches, and Cisco Small Business 500 Series Stackable Managed Switches could allow an unauthenticated, remote attacker to render the web-based management interface unusable, resulting in a denial of service (DoS) condition. This vulnerability is due to improper validation of HTTP requests. An attacker could exploit this vulnerability by sending a crafted HTTP request to an affected device. A successful exploit could allow the attacker to cause a permanent invalid redirect for requests sent to the web-based management interface of the device, resulting in a DoS condition.
A vulnerability in the web-based management interface of multiple Cisco Small Business Series Switches could allow an unauthenticated, remote attacker to replay valid user session credentials and gain unauthorized access to the web-based management interface of an affected device. This vulnerability is due to insufficient expiration of session credentials. An attacker could exploit this vulnerability by conducting a man-in-the-middle attack against an affected device to intercept valid session credentials and then replaying the intercepted credentials toward the same device at a later time. A successful exploit could allow the attacker to access the web-based management interface with administrator privileges.
A vulnerability in the Simple Network Management Protocol (SNMP) subsystem communication channel through the Cisco 550X Series Stackable Managed Switches could allow an authenticated, remote attacker to cause the device to reload unexpectedly, causing a denial of service (DoS) condition. The device nay need to be manually reloaded to recover. The vulnerability is due to lack of proper input throttling of ingress SNMP traffic over an internal interface. An attacker could exploit this vulnerability by sending a crafted, heavy stream of SNMP traffic to the targeted device. An exploit could allow the attacker to cause the device to reload unexpectedly, causing a DoS condition. Cisco Bug IDs: CSCvg22135.