PT-2020-3776 · Cisco · Cisco Nx-Os+1

Hao Wu · Published 2020-08-26 · Updated 2021-08-06 · CVE-2020-3397

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 an affected device to unexpectedly reload, resulting in a denial of service (DoS) condition. The vulnerability is due to incomplete input validation of a specific type of BGP MVPN update message. An attacker could exploit this vulnerability by sending this specific, valid BGP MVPN update message to a targeted device. A successful exploit could allow the attacker to cause one of the BGP-related routing applications to restart multiple times, leading to a system-level restart. Note that 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.

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:2020-04136

CVE-2020-3397

Affected Products

Cisco Nx-Os

Cisco Nexus

References · 5

• https://nvd.nist.gov/vuln/detail/CVE-2020-3397 · Security Note
• https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-nxosbgp-nlri-dos-458rG2OQ · Vendor Advisory
• https://bdu.fstec.ru/vul/2020-04136 · Security Note
• https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-nxosbgp-nlri-dos-458rG2OQ · Vendor Advisory
• https://t.me/cvenotify/18807 · Telegram Post