Cisco IOS XE Software for cBR 8 Converged Broadband Routers DHCP DoS (cisco-sa-iosxe-dhcp-dos-JSCKX43h)

high Nessus Plugin ID 141397
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VPR Score: 4.4


The remote device is missing a vendor-supplied security patch


According to its self-reported version, IOS-XE is affected by a DoS vulnerability in the DHCP message handler of Cisco IOS XE Software for Cisco cBR-8 Converged Broadband Routers due to insufficient error handling when DHCP version 4 (DHCPv4) messages are parsed. An unauthenticated, remote attacker could exploit this vulnerability by sending a malicious DHCPv4 message to or through a WAN interface of an affected device and cause the supervisor to crash and could result in a denial of service (DoS) condition.

This vulnerability only affects Cisco cBR-8 Converged Broadband Routers that are running a vulnerable release of Cisco IOS XE Software and have a WAN interface connected.

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


Upgrade to the relevant fixed version referenced in Cisco bug ID CSCvr70940

See Also

Plugin Details

Severity: High

ID: 141397

File Name: cisco-sa-iosxe-dhcp-dos-JSCKX43h-iosxe.nasl

Version: 1.9

Type: local

Family: CISCO

Published: 10/13/2020

Updated: 3/29/2021

Dependencies: cisco_ios_xe_version.nasl

Configuration: Enable paranoid mode

Risk Information

Risk Factor: High

VPR Score: 4.4

CVSS Score Source: CVE-2020-3509

CVSS v2.0

Base Score: 7.8

Temporal Score: 5.8

Vector: AV:N/AC:L/Au:N/C:N/I:N/A:C

Temporal Vector: E:U/RL:OF/RC:C

CVSS v3.0

Base Score: 8.6

Temporal Score: 7.5

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

Temporal Vector: E:U/RL:O/RC:C

Vulnerability Information

CPE: cpe:/o:cisco:ios_xe

Required KB Items: Host/Cisco/IOS-XE/Version, Settings/ParanoidReport

Exploit Ease: No known exploits are available

Patch Publication Date: 9/24/2020

Vulnerability Publication Date: 9/24/2020

Reference Information

CVE: CVE-2020-3509


CISCO-SA: cisco-sa-iosxe-dhcp-dos-JSCKX43h

IAVA: 2020-A-0439

CWE: 388