Cisco NX-OS Border Gateway Protocol TCP Connection input validation

Summaryinfo

A vulnerability identified as problematic has been detected in Cisco NX-OS. This affects an unknown part of the component Border Gateway Protocol. This manipulation as part of TCP Connection causes input validation. This vulnerability appears as CVE-2020-3397. The attack may be initiated remotely. There is no available exploit. You should upgrade the affected component.

Detailsinfo

A vulnerability has been found in Cisco NX-OS (Router Operating System) (affected version not known) and classified as problematic. Affected by this vulnerability is some unknown functionality of the component Border Gateway Protocol. The manipulation as part of a TCP Connection leads to a input validation vulnerability. The CWE definition for the vulnerability is CWE-20. The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly. As an impact it is known to affect availability. The summary by CVE is:

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 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: 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.

The weakness was presented 08/27/2020 as cisco-sa-nxosbgp-nlri-dos-458r as confirmed advisory (Website). The advisory is shared at tools.cisco.com. This vulnerability is known as CVE-2020-3397 since 12/12/2019. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 11/10/2020).

Upgrading eliminates this vulnerability.

See VDB-160396, VDB-160395, VDB-160394 and VDB-160391 for similar entries. Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Type

• Router Operating System

Vendor

• Cisco

Name

• NX-OS

License

• commercial

Website

• Vendor: https://www.cisco.com/

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CPE 2.2info

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Entryinfo

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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