VU#855201: L2 network security controls can be bypassed using VLAN 0 stacking and/or 802.3 headers

Overview Layer-2 (L2) network security controls provided by various devices, such as switches, routers, and operating systems, can be bypassed by stacking Ethernet protocol headers. An attacker can send crafted packets through vulnerable devices to cause Denial-of-service (DoS) or to perform a man-in-the-middle (MitM) attack against a target network. Description This vulnerability exists within Ethernet encapsulation protocols that allow for stacking of Virtual Local Area Network (VLAN) headers. Network standards such as IEEE 802.1Q-1998 and IEEE 802.3 define a system...