CVE-2020-3398 Information
Description
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.
CVSS Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
Reference
Attack Complexity
LOW
Privileges Required
NONE
User Interaction Required
NONE
Scope
NONE
Confidentiality Impact
CHANGED
Integrity Impact
NONE
Availability Impact
NONE
Base Score
HIGH
Base Severity
8.6
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