A vulnerability in the Border Gateway Protocol (BGP) Multicast VPN (MVPN) implementation of Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause a BGP session to repeatedly reset, causing a partial denial of service (DoS) condition due to the BGP session being down. The vulnerability is due to incorrect parsing of a specific type of BGP MVPN update message. An attacker could exploit this vulnerability by sending this BGP MVPN update message to a targeted device. A successful exploit could allow the attacker to cause the BGP peer connections to reset, which could lead to BGP route instability and impact traffic. The incoming BGP MVPN update message is valid but is parsed incorrectly by the NX-OS device, which could send a corrupted BGP update to the configured BGP peer. Note: The Cisco implementation of BGP accepts incoming BGP traffic from only explicitly configured peers. To exploit this vulnerability, an attacker must send a specific BGP MVPN update message over an established TCP connection that appears to come from a trusted BGP peer. To do so, the attacker must obtain information about the BGP peers in the trusted network of the affected system.

According to its self-reported version, Cisco NX-OS Software is affected by a vulnerability in the Border Gateway Protocol (BVP) Multicast VPN (MVPN) implementation due to incorrect parsing of a specific type of BGP MVPN update message. An unauthenticated, remote attacker can exploit this, by sending this BGP MVPN update message, in order to cause a partial denial of service (DoS) condition due to the BGP session being down.

Please see the included Cisco BIDs and Cisco Security Advisory for more information.

Detections

Analytics

CVE-2020-3398

high

Tenable Plugins

high