PT-2020-3777 · Cisco · Cisco Nx-Os+1

Published 2020-08-26 · Updated 2021-08-06 · CVE-2020-3398

Positive Technologies (AI Summary)

CVSS v3.1

8.6

High

Base vector

AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

Name of the Vulnerable Software and Affected Versions: Cisco NX-OS Software (affected versions not specified)

Description: A vulnerability in the Border Gateway Protocol (BGP) Multicast VPN (MVPN) implementation 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. 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.

Recommendations: At the moment, there is no information about a newer version that contains a fix for this vulnerability.

DoS

RCE

Weakness Enumeration

CWE-20

Related Identifiers

BDU:2020-04137

CVE-2020-3398

Affected Products

Cisco Nx-Os

Cisco Nexus

References · 5

• https://nvd.nist.gov/vuln/detail/CVE-2020-3398 · Security Note
• https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-nxosbgp-mvpn-dos-K8kbCrJp · Vendor Advisory
• https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-nxosbgp-mvpn-dos-K8kbCrJp · Vendor Advisory
• https://bdu.fstec.ru/vul/2020-04137 · Security Note
• https://t.me/cvenotify/18810 · Telegram Post